graphview: Draw links using new gdk path API instead of cairo

update Helvum to track the latest pipewire0.8.0

.gitignore

@@ -1,3 +1,5 @@
+/.flatpak
 /.flatpak-builder
 /.vscode
+/_build
 /target

.gitlab-ci.yml

@@ -1,75 +1,53 @@
-include:
-  - project: 'freedesktop/ci-templates'             # the project to include from
-    ref: '34f4ade99434043f88e164933f570301fd18b125' # git ref of that project
-    file: '/templates/fedora.yml'                   # the actual file to include
-
 stages:
-  - prepare
+  - build
   - lint
-  - test
-  - extras
 
-variables:
+.flatpak:
-  FDO_UPSTREAM_REPO: 'pipewire/helvum'
+  image: 'quay.io/gnome_infrastructure/gnome-runtime-images:gnome-46'
-
-# Version and tag for our current container
-.fedora:
   variables:
-    FDO_DISTRIBUTION_VERSION: '36'
+    FLATPAK_BUILD_DIR: _build
-    # Update this to trigger a container rebuild
+    MANIFEST_PATH: build-aux/org.pipewire.Helvum.json
-    FDO_DISTRIBUTION_TAG: '2022-11-09.0'
+    APP_FLATPAK_MODULE: Helvum
+  before_script:
+    - flatpak --version
+    - flatpak info org.gnome.Platform
+    - flatpak info org.gnome.Sdk
+    - flatpak info org.freedesktop.Sdk.Extension.llvm16
+    - flatpak info org.freedesktop.Sdk.Extension.rust-stable
+    - flatpak-builder --version
 
-build-fedora-container:
+build:
-  extends:
+  stage: build
-  - .fedora                            # our template job above
+  extends: .flatpak
-  - .fdo.container-build@fedora@x86_64 # the CI template
-  stage: prepare
-  variables:
-    # clang-devel: required by rust bindgen
-    FDO_DISTRIBUTION_PACKAGES: >-
-      rust
-      cargo
-      rustfmt
-      clippy
-      pipewire-devel
-      gtk4-devel
-      clang-devel
-
-rustfmt:
-  extends:
-    - .fedora
-    - .fdo.distribution-image@fedora
-  stage: lint
   script:
-    - cargo fmt --version
+    - flatpak-builder --keep-build-dirs --user --disable-rofiles-fuse ${FLATPAK_BUILD_DIR} ${MANIFEST_PATH}
-    - cargo fmt -- --color=always --check
 
-test-stable:
+# TODO: Run meson test
-  extends:
-    - .fedora
-    - .fdo.distribution-image@fedora
-  stage: test
-  script:
-    - rustc --version
-    - cargo build --color=always --all-targets
-    - cargo test --color=always
-
-rustdoc:
-  extends:
-    - .fedora
-    - .fdo.distribution-image@fedora
-  stage: extras
-  variables:
-    RUSTDOCFLAGS: '-Dwarnings'
-  script:
-    - rustdoc --version
-    - cargo doc --no-deps
 
 clippy:
-  extends:
+  stage: lint
-    - .fedora
+  extends: .flatpak
-    - .fdo.distribution-image@fedora
-  stage: extras
   script:
-    - cargo clippy --version
+    - flatpak-builder --keep-build-dirs --user --disable-rofiles-fuse --stop-at=${APP_FLATPAK_MODULE} ${FLATPAK_BUILD_DIR} ${MANIFEST_PATH}
-    - cargo clippy --color=always --all-targets -- -D warnings
+    - >-
+      flatpak-builder --run ${FLATPAK_BUILD_DIR} ${MANIFEST_PATH}
+      cargo clippy --color=always --all-targets -- -D warnings
+
+rustfmt:
+  stage: lint
+  image: "rust:slim" # TODO: Check image
+  script:
+    - rustup component add rustfmt
+    - rustc -Vv && cargo -Vv
+    - cargo fmt --version
+    - cargo fmt --all -- --color=always --check
+
+rustdoc:
+  stage: lint
+  extends: .flatpak
+  script:
+    - flatpak-builder --keep-build-dirs --user --disable-rofiles-fuse --stop-at=${APP_FLATPAK_MODULE} ${FLATPAK_BUILD_DIR} ${MANIFEST_PATH}
+    - >-
+      flatpak-builder --run ${FLATPAK_BUILD_DIR} ${MANIFEST_PATH}
+      env RUSTDOCFLAGS=-Dwarnings cargo doc --no-deps
+

Cargo.toml

@@ -1,9 +1,9 @@
 [package]
 name = "helvum"
-version = "0.4.0"
+version = "0.5.1"
-authors = ["Tom A. Wagner <tom.a.wagner@protonmail.com>"]
+authors = ["Tom Wagner <tom.a.wagner@protonmail.com>"]
 edition = "2021"
-rust-version = "1.56"
+rust-version = "1.70"
 license = "GPL-3.0-only"
 description = "A GTK patchbay for pipewire"
 repository = "https://gitlab.freedesktop.org/pipewire/helvum"
@@ -14,10 +14,14 @@ categories = ["gui", "multimedia"]
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-pipewire = "0.6"
+pipewire = "0.8.0"
-gtk = { version = "0.6", package = "gtk4" }
+adw = { version = "0.6", package = "libadwaita", features = ["v1_4"] }
-glib = { version = "0.17", features = ["log"] }
+gtk = { version = "0.8", package = "gtk4", features = ["v4_14"] }
+glib = { version = "0.19", features = ["log"] }
+async-channel = "2.2"
 
 log = "0.4.11"
 
-once_cell = "1.7.2"
+once_cell = "1.19"
+
+libc = "0.2"

README.md

@@ -23,7 +23,7 @@ $ flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.fl
 
 Then install the required flatpak platform and SDK, if you dont have them already:
 ```shell
-$ flatpak install org.gnome.{Platform,Sdk}//43 org.freedesktop.Sdk.Extension.rust-stable//22.08 org.freedesktop.Sdk.Extension.llvm14//22.08
+$ flatpak install org.gnome.{Platform,Sdk}//46 org.freedesktop.Sdk.Extension.rust-stable//23.08 org.freedesktop.Sdk.Extension.llvm16//23.08
 ```
 
 To compile and install as a flatpak, clone the project, change to the project directory, and run:
@@ -42,7 +42,7 @@ For compilation, you will need:
 - Meson
 - An up-to-date rust toolchain
 - `libclang-3.7` or higher
-- `gtk-4.0` and `pipewire-0.3` development headers
+- `libadwaita-1` and `libpipewire-0.3` development packages and their dependencies
 
 To compile and install, run
 

build-aux/org.pipewire.Helvum.json

@@ -1,11 +1,11 @@
 {
-    "app-id": "org.pipewire.Helvum",
+    "id": "org.pipewire.Helvum",
     "runtime": "org.gnome.Platform",
-    "runtime-version": "43",
+    "runtime-version": "46",
     "sdk": "org.gnome.Sdk",
     "sdk-extensions": [
         "org.freedesktop.Sdk.Extension.rust-stable",
-        "org.freedesktop.Sdk.Extension.llvm14"
+        "org.freedesktop.Sdk.Extension.llvm16"
     ],
     "command": "helvum",
     "finish-args": [
@@ -16,8 +16,8 @@
         "--filesystem=xdg-run/pipewire-0"
     ],
     "build-options": {
-        "append-path": "/usr/lib/sdk/rust-stable/bin:/usr/lib/sdk/llvm14/bin",
+        "append-path": "/usr/lib/sdk/rust-stable/bin:/usr/lib/sdk/llvm16/bin",
-        "prepend-ld-library-path": "/usr/lib/sdk/llvm14/lib",
+        "prepend-ld-library-path": "/usr/lib/sdk/llvm16/lib",
         "build-args": [
             "--share=network"
         ]

data/org.pipewire.Helvum.metainfo.xml.in

@@ -23,6 +23,9 @@
     <url type="bugtracker">https://gitlab.freedesktop.org/pipewire/helvum/-/issues</url>
     <content_rating type="oars-1.0" />
     <releases>
+        <release version="0.5.1" date="2023-09-28" />
+        <release version="0.5.0" date="2023-09-28" />
+        <release version="0.4.1" date="2023-08-18" />
         <release version="0.4.0" date="2023-02-12" />
         <release version="0.3.4" date="2022-02-02" />
         <release version="0.3.3" date="2022-01-28" />

meson.build

@@ -1,7 +1,7 @@
 project(
   'helvum',
   'rust',
-  version: '0.4.0',
+  version: '0.5.1',
   license: 'GPL-3.0',
   meson_version: '>=0.59.0'
 )
@@ -10,8 +10,9 @@ gnome = import('gnome')
 
 base_id = 'org.pipewire.Helvum'
 
-dependency('glib-2.0', version: '>= 2.66')
+dependency('glib-2.0',     version: '>= 2.66')
-dependency('gtk4',     version: '>= 4.4.0')
+dependency('gtk4',         version: '>= 4.14.0')
+dependency('libadwaita-1', version: '>= 1.4')
 dependency('libpipewire-0.3')
 
 desktop_file_validate = find_program('desktop-file-validate', required: false)

src/application.rs

@@ -14,97 +14,129 @@
 //
 // SPDX-License-Identifier: GPL-3.0-only
 
-use std::cell::RefCell;
+use adw::{
-
-use gtk::{
     gio,
-    glib::{self, clone, Continue, Receiver},
+    glib::{self, clone},
+    gtk,
     prelude::*,
     subclass::prelude::*,
 };
-use log::info;
+use pipewire::channel::Sender;
-use pipewire::{channel::Sender, spa::Direction};
 
-use crate::{
+use crate::{graph_manager::GraphManager, ui, GtkMessage, PipewireMessage};
-    view::{self},
-    GtkMessage, MediaType, NodeType, PipewireLink, PipewireMessage,
-};
 
 static STYLE: &str = include_str!("style.css");
+static APP_ID: &str = "org.pipewire.Helvum";
+static VERSION: &str = env!("CARGO_PKG_VERSION");
+static AUTHORS: &str = env!("CARGO_PKG_AUTHORS");
 
 mod imp {
     use super::*;
 
-    use once_cell::unsync::OnceCell;
+    use std::cell::OnceCell;
+
+    use adw::subclass::prelude::AdwApplicationImpl;
 
     #[derive(Default)]
     pub struct Application {
-        pub(super) graphview: view::GraphView,
+        pub(super) window: ui::Window,
-        pub(super) pw_sender: OnceCell<RefCell<Sender<GtkMessage>>>,
+        pub(super) graph_manager: OnceCell<GraphManager>,
     }
 
     #[glib::object_subclass]
     impl ObjectSubclass for Application {
         const NAME: &'static str = "HelvumApplication";
         type Type = super::Application;
-        type ParentType = gtk::Application;
+        type ParentType = adw::Application;
     }
 
     impl ObjectImpl for Application {}
     impl ApplicationImpl for Application {
         fn activate(&self) {
             let app = &*self.obj();
-            let scrollwindow = gtk::ScrolledWindow::builder()
-                .child(&self.graphview)
-                .build();
-            let headerbar = gtk::HeaderBar::new();
-            let zoomentry = view::ZoomEntry::new(&self.graphview);
-            headerbar.pack_end(&zoomentry);
 
-            let window = gtk::ApplicationWindow::builder()
+            let graphview = self.window.graph();
-                .application(app)
+
-                .default_width(1280)
+            self.window.set_application(Some(app));
-                .default_height(720)
-                .title("Helvum - Pipewire Patchbay")
-                .child(&scrollwindow)
-                .build();
-            window
-                .settings()
-                .set_gtk_application_prefer_dark_theme(true);
-            window.set_titlebar(Some(&headerbar));
 
             let zoom_set_action =
                 gio::SimpleAction::new("set-zoom", Some(&f64::static_variant_type()));
-            zoom_set_action.connect_activate(
+            zoom_set_action.connect_activate(clone!(@weak graphview => move|_, param| {
-                clone!(@weak self.graphview as graphview => move|_, param| {
+                let zoom_factor = param.unwrap().get::<f64>().unwrap();
-                    let zoom_factor = param.unwrap().get::<f64>().unwrap();
+                graphview.set_zoom_factor(zoom_factor, None)
-                    graphview.set_zoom_factor(zoom_factor, None)
+            }));
-                }),
+            self.window.add_action(&zoom_set_action);
-            );
-            window.add_action(&zoom_set_action);
 
-            window.show();
+            self.window.show();
         }
 
         fn startup(&self) {
             self.parent_startup();
 
+            self.obj()
+                .style_manager()
+                .set_color_scheme(adw::ColorScheme::PreferDark);
+
             // Load CSS from the STYLE variable.
             let provider = gtk::CssProvider::new();
             provider.load_from_data(STYLE);
-            gtk::StyleContext::add_provider_for_display(
+            gtk::style_context_add_provider_for_display(
                 &gtk::gdk::Display::default().expect("Error initializing gtk css provider."),
                 &provider,
                 gtk::STYLE_PROVIDER_PRIORITY_APPLICATION,
             );
+
+            self.setup_actions();
         }
     }
     impl GtkApplicationImpl for Application {}
+    impl AdwApplicationImpl for Application {}
+
+    impl Application {
+        fn setup_actions(&self) {
+            let obj = &*self.obj();
+
+            // Add <Control-Q> shortcut for quitting the application.
+            let quit = gtk::gio::SimpleAction::new("quit", None);
+            quit.connect_activate(clone!(@weak obj => move |_, _| {
+                obj.quit();
+            }));
+            obj.set_accels_for_action("app.quit", &["<Control>Q"]);
+            obj.add_action(&quit);
+
+            let action_about = gio::ActionEntry::builder("about")
+                .activate(|obj: &super::Application, _, _| {
+                    obj.imp().show_about_dialog();
+                })
+                .build();
+            obj.add_action_entries([action_about]);
+        }
+
+        fn show_about_dialog(&self) {
+            let obj = &*self.obj();
+            let window = obj.active_window().unwrap();
+            let authors: Vec<&str> = AUTHORS.split(':').collect();
+
+            let about_window = adw::AboutWindow::builder()
+                .transient_for(&window)
+                .application_icon(APP_ID)
+                .application_name("Helvum")
+                .developer_name("Tom Wagner")
+                .developers(authors)
+                .version(VERSION)
+                .website("https://gitlab.freedesktop.org/pipewire/helvum")
+                .issue_url("https://gitlab.freedesktop.org/pipewire/helvum/-/issues")
+                .license_type(gtk::License::Gpl30Only)
+                .build();
+
+            about_window.present();
+        }
+    }
 }
 
 glib::wrapper! {
     pub struct Application(ObjectSubclass<imp::Application>)
-        @extends gio::Application, gtk::Application,
+        @extends gio::Application, gtk::Application, adw::Application,
         @implements gio::ActionGroup, gio::ActionMap;
 }
 
@@ -112,160 +144,24 @@ impl Application {
     /// Create the view.
     /// This will set up the entire user interface and prepare it for being run.
     pub(super) fn new(
-        gtk_receiver: Receiver<PipewireMessage>,
+        gtk_receiver: async_channel::Receiver<PipewireMessage>,
         pw_sender: Sender<GtkMessage>,
     ) -> Self {
         let app: Application = glib::Object::builder()
-            .property("application-id", &"org.pipewire.Helvum")
+            .property("application-id", APP_ID)
             .build();
 
         let imp = app.imp();
-        imp.pw_sender
-            .set(RefCell::new(pw_sender))
-            // Discard the returned sender, as it does not implement `Debug`.
-            .map_err(|_| ())
-            .expect("pw_sender field was already set");
 
-        // Add <Control-Q> shortcut for quitting the application.
+        imp.graph_manager
-        let quit = gtk::gio::SimpleAction::new("quit", None);
+            .set(GraphManager::new(
-        quit.connect_activate(clone!(@weak app => move |_, _| {
+                &imp.window.graph(),
-            app.quit();
+                &imp.window.connection_banner(),
-        }));
+                pw_sender,
-        app.set_accels_for_action("app.quit", &["<Control>Q"]);
+                gtk_receiver,
-        app.add_action(&quit);
+            ))
-
+            .expect("Should be able to set graph manager");
-        // React to messages received from the pipewire thread.
-        gtk_receiver.attach(
-            None,
-            clone!(
-                @weak app => @default-return Continue(true),
-                move |msg| {
-                    match msg {
-                        PipewireMessage::NodeAdded{ id, name, node_type } => app.add_node(id, name.as_str(), node_type),
-                        PipewireMessage::PortAdded{ id, node_id, name, direction, media_type } => app.add_port(id, name.as_str(), node_id, direction, media_type),
-                        PipewireMessage::LinkAdded{ id, node_from, port_from, node_to, port_to, active} => app.add_link(id, node_from, port_from, node_to, port_to, active),
-                        PipewireMessage::LinkStateChanged { id, active } => app.link_state_changed(id, active), // TODO
-                        PipewireMessage::NodeRemoved { id } => app.remove_node(id),
-                        PipewireMessage::PortRemoved { id, node_id } => app.remove_port(id, node_id),
-                        PipewireMessage::LinkRemoved { id } => app.remove_link(id)
-                    };
-                    Continue(true)
-                }
-            ),
-        );
 
         app
     }
-
-    /// Add a new node to the view.
-    fn add_node(&self, id: u32, name: &str, node_type: Option<NodeType>) {
-        info!("Adding node to graph: id {}", id);
-
-        self.imp()
-            .graphview
-            .add_node(id, view::Node::new(name, id), node_type);
-    }
-
-    /// Add a new port to the view.
-    fn add_port(
-        &self,
-        id: u32,
-        name: &str,
-        node_id: u32,
-        direction: Direction,
-        media_type: Option<MediaType>,
-    ) {
-        info!("Adding port to graph: id {}", id);
-
-        let port = view::Port::new(id, name, direction, media_type);
-
-        // Create or delete a link if the widget emits the "port-toggled" signal.
-        port.connect_local(
-            "port_toggled",
-            false,
-            clone!(@weak self as app => @default-return None, move |args| {
-                // Args always look like this: &[widget, id_port_from, id_port_to]
-                let port_from = args[1].get::<u32>().unwrap();
-                let port_to = args[2].get::<u32>().unwrap();
-
-                app.toggle_link(port_from, port_to);
-
-                None
-            }),
-        );
-
-        self.imp().graphview.add_port(node_id, id, port);
-    }
-
-    /// Add a new link to the view.
-    fn add_link(
-        &self,
-        id: u32,
-        node_from: u32,
-        port_from: u32,
-        node_to: u32,
-        port_to: u32,
-        active: bool,
-    ) {
-        info!("Adding link to graph: id {}", id);
-
-        // FIXME: Links should be colored depending on the data they carry (video, audio, midi) like ports are.
-
-        // Update graph to contain the new link.
-        self.imp().graphview.add_link(
-            id,
-            PipewireLink {
-                node_from,
-                port_from,
-                node_to,
-                port_to,
-            },
-            active,
-        );
-    }
-
-    fn link_state_changed(&self, id: u32, active: bool) {
-        info!(
-            "Link state changed: Link (id={}) is now {}",
-            id,
-            if active { "active" } else { "inactive" }
-        );
-
-        self.imp().graphview.set_link_state(id, active);
-    }
-
-    // Toggle a link between the two specified ports on the remote pipewire server.
-    fn toggle_link(&self, port_from: u32, port_to: u32) {
-        let sender = self
-            .imp()
-            .pw_sender
-            .get()
-            .expect("pw_sender not set")
-            .borrow_mut();
-        sender
-            .send(GtkMessage::ToggleLink { port_from, port_to })
-            .expect("Failed to send message");
-    }
-
-    /// Remove the node with the specified id from the view.
-    fn remove_node(&self, id: u32) {
-        info!("Removing node from graph: id {}", id);
-
-        self.imp().graphview.remove_node(id);
-    }
-
-    /// Remove the port with the id `id` from the node with the id `node_id`
-    /// from the view.
-    fn remove_port(&self, id: u32, node_id: u32) {
-        info!("Removing port from graph: id {}, node_id: {}", id, node_id);
-
-        self.imp().graphview.remove_port(id, node_id);
-    }
-
-    /// Remove the link with the specified id from the view.
-    fn remove_link(&self, id: u32) {
-        info!("Removing link from graph: id {}", id);
-
-        self.imp().graphview.remove_link(id);
-    }
 }

src/graph_manager.rs

@@ -0,0 +1,379 @@
+// Copyright 2021 Tom A. Wagner <tom.a.wagner@protonmail.com>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License version 3 as published by
+// the Free Software Foundation.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+// SPDX-License-Identifier: GPL-3.0-only
+
+use adw::{glib, prelude::*, subclass::prelude::*};
+
+use pipewire::channel::Sender as PwSender;
+
+use crate::{ui::graph::GraphView, GtkMessage, PipewireMessage};
+
+mod imp {
+    use super::*;
+
+    use std::{cell::OnceCell, cell::RefCell, collections::HashMap};
+
+    use crate::{ui::graph, MediaType, NodeType};
+
+    #[derive(Default, glib::Properties)]
+    #[properties(wrapper_type = super::GraphManager)]
+    pub struct GraphManager {
+        #[property(get, set, construct_only)]
+        pub graph: OnceCell<crate::ui::graph::GraphView>,
+
+        #[property(get, set, construct_only)]
+        pub connection_banner: OnceCell<adw::Banner>,
+
+        pub pw_sender: OnceCell<PwSender<crate::GtkMessage>>,
+        pub items: RefCell<HashMap<u32, glib::Object>>,
+    }
+
+    #[glib::object_subclass]
+    impl ObjectSubclass for GraphManager {
+        const NAME: &'static str = "HelvumGraphManager";
+        type Type = super::GraphManager;
+        type ParentType = glib::Object;
+    }
+
+    #[glib::derived_properties]
+    impl ObjectImpl for GraphManager {}
+
+    impl GraphManager {
+        pub async fn receive(&self, receiver: async_channel::Receiver<crate::PipewireMessage>) {
+            loop {
+                let Ok(msg) = receiver.recv().await else {
+                    continue;
+                };
+                match msg {
+                    PipewireMessage::NodeAdded {
+                        id,
+                        name,
+                        node_type,
+                    } => self.add_node(id, name.as_str(), node_type),
+                    PipewireMessage::NodeNameChanged {
+                        id,
+                        name,
+                        media_name,
+                    } => self.node_name_changed(id, &name, &media_name),
+                    PipewireMessage::PortAdded {
+                        id,
+                        node_id,
+                        name,
+                        direction,
+                    } => self.add_port(id, name.as_str(), node_id, direction),
+                    PipewireMessage::PortFormatChanged { id, media_type } => {
+                        self.port_media_type_changed(id, media_type)
+                    }
+                    PipewireMessage::LinkAdded {
+                        id,
+                        port_from,
+                        port_to,
+                        active,
+                        media_type,
+                    } => self.add_link(id, port_from, port_to, active, media_type),
+                    PipewireMessage::LinkStateChanged { id, active } => {
+                        self.link_state_changed(id, active)
+                    }
+                    PipewireMessage::LinkFormatChanged { id, media_type } => {
+                        self.link_format_changed(id, media_type)
+                    }
+                    PipewireMessage::NodeRemoved { id } => self.remove_node(id),
+                    PipewireMessage::PortRemoved { id, node_id } => self.remove_port(id, node_id),
+                    PipewireMessage::LinkRemoved { id } => self.remove_link(id),
+                    PipewireMessage::Connecting => {
+                        self.obj().connection_banner().set_revealed(true);
+                    }
+                    PipewireMessage::Connected => {
+                        self.obj().connection_banner().set_revealed(false);
+                    }
+                    PipewireMessage::Disconnected => {
+                        self.clear();
+                    }
+                };
+            }
+        }
+
+        /// Add a new node to the view.
+        fn add_node(&self, id: u32, name: &str, node_type: Option<NodeType>) {
+            log::info!("Adding node to graph: id {}", id);
+
+            let node = graph::Node::new(name, id);
+
+            self.items.borrow_mut().insert(id, node.clone().upcast());
+
+            self.obj().graph().add_node(node, node_type);
+        }
+
+        /// Update a node tooltip to the view.
+        fn node_name_changed(&self, id: u32, node_name: &str, media_name: &str) {
+            let items = self.items.borrow();
+
+            let Some(node) = items.get(&id) else {
+                log::warn!("Node (id: {id}) for changed name not found in graph manager");
+                return;
+            };
+            let Some(node) = node.dynamic_cast_ref::<graph::Node>() else {
+                log::warn!("Graph Manager item under node (id: {id}) is not a node");
+                return;
+            };
+
+            node.set_node_name(node_name);
+            node.set_media_name(media_name);
+        }
+
+        /// Remove the node with the specified id from the view.
+        fn remove_node(&self, id: u32) {
+            log::info!("Removing node from graph: id {}", id);
+
+            let Some(node) = self.items.borrow_mut().remove(&id) else {
+                log::warn!("Unknown node (id={id}) removed from graph");
+                return;
+            };
+            let Ok(node) = node.dynamic_cast::<graph::Node>() else {
+                log::warn!("Graph Manager item under node id {id} is not a node");
+                return;
+            };
+
+            self.obj().graph().remove_node(&node);
+        }
+
+        /// Add a new port to the view.
+        fn add_port(
+            &self,
+            id: u32,
+            name: &str,
+            node_id: u32,
+            direction: pipewire::spa::utils::Direction,
+        ) {
+            log::info!("Adding port to graph: id {}", id);
+
+            let mut items = self.items.borrow_mut();
+
+            let Some(node) = items.get(&node_id) else {
+                log::warn!("Node (id: {node_id}) for port (id: {id}) not found in graph manager");
+                return;
+            };
+            let Ok(node) = node.clone().dynamic_cast::<graph::Node>() else {
+                log::warn!("Graph Manager item under node id {node_id} is not a node");
+                return;
+            };
+
+            let port = graph::Port::new(id, name, direction);
+
+            // Create or delete a link if the widget emits the "port-toggled" signal.
+            port.connect_local(
+                "port_toggled",
+                false,
+                glib::clone!(@weak self as app => @default-return None, move |args| {
+                    // Args always look like this: &[widget, id_port_from, id_port_to]
+                    let port_from = args[1].get::<u32>().unwrap();
+                    let port_to = args[2].get::<u32>().unwrap();
+
+                    app.toggle_link(port_from, port_to);
+
+                    None
+                }),
+            );
+
+            items.insert(id, port.clone().upcast());
+
+            node.add_port(port);
+        }
+
+        fn port_media_type_changed(&self, id: u32, media_type: MediaType) {
+            let items = self.items.borrow();
+
+            let Some(port) = items.get(&id) else {
+                log::warn!("Port (id: {id}) for changed media type not found in graph manager");
+                return;
+            };
+            let Some(port) = port.dynamic_cast_ref::<graph::Port>() else {
+                log::warn!("Graph Manager item under port id {id} is not a port");
+                return;
+            };
+
+            port.set_media_type(media_type.as_raw())
+        }
+
+        /// Remove the port with the id `id` from the node with the id `node_id`
+        /// from the view.
+        fn remove_port(&self, id: u32, node_id: u32) {
+            log::info!("Removing port from graph: id {}, node_id: {}", id, node_id);
+
+            let mut items = self.items.borrow_mut();
+
+            let Some(node) = items.get(&node_id) else {
+                log::warn!("Node (id: {node_id}) for port (id: {id}) not found in graph manager");
+                return;
+            };
+            let Ok(node) = node.clone().dynamic_cast::<graph::Node>() else {
+                log::warn!("Graph Manager item under node id {node_id} is not a node");
+                return;
+            };
+            let Some(port) = items.remove(&id) else {
+                log::warn!("Unknown Port (id: {id}) removed from graph");
+                return;
+            };
+            let Ok(port) = port.dynamic_cast::<graph::Port>() else {
+                log::warn!("Graph Manager item under port id {id} is not a port");
+                return;
+            };
+
+            node.remove_port(&port);
+        }
+
+        /// Add a new link to the view.
+        fn add_link(
+            &self,
+            id: u32,
+            output_port_id: u32,
+            input_port_id: u32,
+            active: bool,
+            media_type: MediaType,
+        ) {
+            log::info!("Adding link to graph: id {}", id);
+
+            let mut items = self.items.borrow_mut();
+
+            let Some(output_port) = items.get(&output_port_id) else {
+                log::warn!("Output port (id: {output_port_id}) for link (id: {id}) not found in graph manager");
+                return;
+            };
+            let Ok(output_port) = output_port.clone().dynamic_cast::<graph::Port>() else {
+                log::warn!("Graph Manager item under port id {output_port_id} is not a port");
+                return;
+            };
+            let Some(input_port) = items.get(&input_port_id) else {
+                log::warn!("Output port (id: {input_port_id}) for link (id: {id}) not found in graph manager");
+                return;
+            };
+            let Ok(input_port) = input_port.clone().dynamic_cast::<graph::Port>() else {
+                log::warn!("Graph Manager item under port id {input_port_id} is not a port");
+                return;
+            };
+
+            let link = graph::Link::new();
+            link.set_output_port(Some(&output_port));
+            link.set_input_port(Some(&input_port));
+            link.set_active(active);
+            link.set_media_type(media_type);
+
+            items.insert(id, link.clone().upcast());
+
+            // Update graph to contain the new link.
+            self.graph
+                .get()
+                .expect("graph should be set")
+                .add_link(link);
+        }
+
+        fn link_state_changed(&self, id: u32, active: bool) {
+            log::info!(
+                "Link state changed: Link (id={id}) is now {}",
+                if active { "active" } else { "inactive" }
+            );
+
+            let items = self.items.borrow();
+
+            let Some(link) = items.get(&id) else {
+                log::warn!("Link state changed on unknown link (id={id})");
+                return;
+            };
+            let Some(link) = link.dynamic_cast_ref::<graph::Link>() else {
+                log::warn!("Graph Manager item under link id {id} is not a link");
+                return;
+            };
+
+            link.set_active(active);
+        }
+
+        fn link_format_changed(
+            &self,
+            id: u32,
+            media_type: pipewire::spa::param::format::MediaType,
+        ) {
+            let items = self.items.borrow();
+
+            let Some(link) = items.get(&id) else {
+                log::warn!("Link (id: {id}) for changed media type not found in graph manager");
+                return;
+            };
+            let Some(link) = link.dynamic_cast_ref::<graph::Link>() else {
+                log::warn!("Graph Manager item under link id {id} is not a link");
+                return;
+            };
+            link.set_media_type(media_type);
+        }
+
+        // Toggle a link between the two specified ports on the remote pipewire server.
+        fn toggle_link(&self, port_from: u32, port_to: u32) {
+            let sender = self.pw_sender.get().expect("pw_sender shoud be set");
+            sender
+                .send(crate::GtkMessage::ToggleLink { port_from, port_to })
+                .expect("Failed to send message");
+        }
+
+        /// Remove the link with the specified id from the view.
+        fn remove_link(&self, id: u32) {
+            log::info!("Removing link from graph: id {}", id);
+
+            let Some(link) = self.items.borrow_mut().remove(&id) else {
+                log::warn!("Unknown Link (id={id}) removed from graph");
+                return;
+            };
+            let Ok(link) = link.dynamic_cast::<graph::Link>() else {
+                log::warn!("Graph Manager item under link id {id} is not a link");
+                return;
+            };
+
+            self.obj().graph().remove_link(&link);
+        }
+
+        fn clear(&self) {
+            self.items.borrow_mut().clear();
+            self.obj().graph().clear();
+        }
+    }
+}
+
+glib::wrapper! {
+    pub struct GraphManager(ObjectSubclass<imp::GraphManager>);
+}
+
+async fn receive(graph_manager: GraphManager, receiver: async_channel::Receiver<PipewireMessage>) {
+    graph_manager.imp().receive(receiver).await
+}
+
+impl GraphManager {
+    pub fn new(
+        graph: &GraphView,
+        connection_banner: &adw::Banner,
+        sender: PwSender<GtkMessage>,
+        receiver: async_channel::Receiver<PipewireMessage>,
+    ) -> Self {
+        let res: Self = glib::Object::builder()
+            .property("graph", graph)
+            .property("connection-banner", connection_banner)
+            .build();
+
+        glib::MainContext::default().spawn_local(receive(res.clone(), receiver));
+        assert!(
+            res.imp().pw_sender.set(sender).is_ok(),
+            "Should be able to set pw_sender)"
+        );
+
+        res
+    }
+}

src/main.rs

@@ -15,16 +15,16 @@
 // SPDX-License-Identifier: GPL-3.0-only
 
 mod application;
+mod graph_manager;
 mod pipewire_connection;
-mod view;
+mod ui;
 
-use glib::PRIORITY_DEFAULT;
+use adw::{gtk, prelude::*};
-use gtk::prelude::*;
+use pipewire::spa::{param::format::MediaType, utils::Direction};
-use pipewire::spa::Direction;
 
 /// Messages sent by the GTK thread to notify the pipewire thread.
 #[derive(Debug, Clone)]
-enum GtkMessage {
+pub enum GtkMessage {
     /// Toggle a link between the two specified ports.
     ToggleLink { port_from: u32, port_to: u32 },
     /// Quit the event loop and let the thread finish.
@@ -33,31 +33,42 @@ enum GtkMessage {
 
 /// Messages sent by the pipewire thread to notify the GTK thread.
 #[derive(Debug, Clone)]
-enum PipewireMessage {
+pub enum PipewireMessage {
     NodeAdded {
         id: u32,
         name: String,
         node_type: Option<NodeType>,
     },
+    NodeNameChanged {
+        id: u32,
+        name: String,
+        media_name: String,
+    },
     PortAdded {
         id: u32,
         node_id: u32,
         name: String,
         direction: Direction,
-        media_type: Option<MediaType>,
+    },
+    PortFormatChanged {
+        id: u32,
+        media_type: MediaType,
     },
     LinkAdded {
         id: u32,
-        node_from: u32,
         port_from: u32,
-        node_to: u32,
         port_to: u32,
         active: bool,
+        media_type: MediaType,
     },
     LinkStateChanged {
         id: u32,
         active: bool,
     },
+    LinkFormatChanged {
+        id: u32,
+        media_type: MediaType,
+    },
     NodeRemoved {
         id: u32,
     },
@@ -68,6 +79,9 @@ enum PipewireMessage {
     LinkRemoved {
         id: u32,
     },
+    Connecting,
+    Connected,
+    Disconnected,
 }
 
 #[derive(Debug, Clone)]
@@ -76,13 +90,6 @@ pub enum NodeType {
     Output,
 }
 
-#[derive(Debug, Copy, Clone)]
-pub enum MediaType {
-    Audio,
-    Video,
-    Midi,
-}
-
 #[derive(Debug, Clone)]
 pub struct PipewireLink {
     pub node_from: u32,
@@ -112,7 +119,8 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     let _guard = ctx.acquire().unwrap();
 
     // Start the pipewire thread with channels in both directions.
-    let (gtk_sender, gtk_receiver) = glib::MainContext::channel(PRIORITY_DEFAULT);
+
+    let (gtk_sender, gtk_receiver) = async_channel::unbounded();
     let (pw_sender, pw_receiver) = pipewire::channel::channel();
     let pw_thread =
         std::thread::spawn(move || pipewire_connection::thread_main(gtk_sender, pw_receiver));

src/pipewire_connection.rs

@@ -1,318 +0,0 @@
-// Copyright 2021 Tom A. Wagner <tom.a.wagner@protonmail.com>
-//
-// This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License version 3 as published by
-// the Free Software Foundation.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License
-// along with this program.  If not, see <http://www.gnu.org/licenses/>.
-//
-// SPDX-License-Identifier: GPL-3.0-only
-
-mod state;
-
-use std::{cell::RefCell, collections::HashMap, rc::Rc};
-
-use gtk::glib::{self, clone};
-use log::{debug, info, warn};
-use pipewire::{
-    link::{Link, LinkChangeMask, LinkListener, LinkState},
-    prelude::*,
-    properties,
-    registry::{GlobalObject, Registry},
-    spa::{Direction, ForeignDict},
-    types::ObjectType,
-    Context, Core, MainLoop,
-};
-
-use crate::{GtkMessage, MediaType, NodeType, PipewireMessage};
-use state::{Item, State};
-
-enum ProxyItem {
-    Link {
-        _proxy: Link,
-        _listener: LinkListener,
-    },
-}
-
-/// The "main" function of the pipewire thread.
-pub(super) fn thread_main(
-    gtk_sender: glib::Sender<PipewireMessage>,
-    pw_receiver: pipewire::channel::Receiver<GtkMessage>,
-) {
-    let mainloop = MainLoop::new().expect("Failed to create mainloop");
-    let context = Context::new(&mainloop).expect("Failed to create context");
-    let core = Rc::new(context.connect(None).expect("Failed to connect to remote"));
-    let registry = Rc::new(core.get_registry().expect("Failed to get registry"));
-
-    // Keep proxies and their listeners alive so that we can receive info events.
-    let proxies = Rc::new(RefCell::new(HashMap::new()));
-
-    let state = Rc::new(RefCell::new(State::new()));
-
-    let _receiver = pw_receiver.attach(&mainloop, {
-        clone!(@strong mainloop, @weak core, @weak registry, @strong state => move |msg| match msg {
-            GtkMessage::ToggleLink { port_from, port_to } => toggle_link(port_from, port_to, &core, &registry, &state),
-            GtkMessage::Terminate => mainloop.quit(),
-        })
-    });
-
-    let _listener = registry
-        .add_listener_local()
-        .global(clone!(@strong gtk_sender, @weak registry, @strong proxies, @strong state =>
-            move |global| match global.type_ {
-                ObjectType::Node => handle_node(global, &gtk_sender, &state),
-                ObjectType::Port => handle_port(global, &gtk_sender, &state),
-                ObjectType::Link => handle_link(global, &gtk_sender, &registry, &proxies, &state),
-                _ => {
-                    // Other objects are not interesting to us
-                }
-            }
-        ))
-        .global_remove(clone!(@strong proxies, @strong state => move |id| {
-            if let Some(item) = state.borrow_mut().remove(id) {
-                gtk_sender.send(match item {
-                    Item::Node { .. } => PipewireMessage::NodeRemoved {id},
-                    Item::Port { node_id } => PipewireMessage::PortRemoved {id, node_id},
-                    Item::Link { .. } => PipewireMessage::LinkRemoved {id},
-                }).expect("Failed to send message");
-            } else {
-                warn!(
-                    "Attempted to remove item with id {} that is not saved in state",
-                    id
-                );
-            }
-
-            proxies.borrow_mut().remove(&id);
-        }))
-        .register();
-
-    mainloop.run();
-}
-
-/// Handle a new node being added
-fn handle_node(
-    node: &GlobalObject<ForeignDict>,
-    sender: &glib::Sender<PipewireMessage>,
-    state: &Rc<RefCell<State>>,
-) {
-    let props = node
-        .props
-        .as_ref()
-        .expect("Node object is missing properties");
-
-    // Get the nicest possible name for the node, using a fallback chain of possible name attributes.
-    let name = String::from(
-        props
-            .get("node.description")
-            .or_else(|| props.get("node.nick"))
-            .or_else(|| props.get("node.name"))
-            .unwrap_or_default(),
-    );
-
-    // FIXME: Instead of checking these props, the "EnumFormat" parameter should be checked instead.
-    let media_type = props.get("media.class").and_then(|class| {
-        if class.contains("Audio") {
-            Some(MediaType::Audio)
-        } else if class.contains("Video") {
-            Some(MediaType::Video)
-        } else if class.contains("Midi") {
-            Some(MediaType::Midi)
-        } else {
-            None
-        }
-    });
-
-    let media_class = |class: &str| {
-        if class.contains("Sink") || class.contains("Input") {
-            Some(NodeType::Input)
-        } else if class.contains("Source") || class.contains("Output") {
-            Some(NodeType::Output)
-        } else {
-            None
-        }
-    };
-
-    let node_type = props
-        .get("media.category")
-        .and_then(|class| {
-            if class.contains("Duplex") {
-                None
-            } else {
-                props.get("media.class").and_then(media_class)
-            }
-        })
-        .or_else(|| props.get("media.class").and_then(media_class));
-
-    state.borrow_mut().insert(
-        node.id,
-        Item::Node {
-            // widget: node_widget,
-            media_type,
-        },
-    );
-
-    sender
-        .send(PipewireMessage::NodeAdded {
-            id: node.id,
-            name,
-            node_type,
-        })
-        .expect("Failed to send message");
-}
-
-/// Handle a new port being added
-fn handle_port(
-    port: &GlobalObject<ForeignDict>,
-    sender: &glib::Sender<PipewireMessage>,
-    state: &Rc<RefCell<State>>,
-) {
-    let props = port
-        .props
-        .as_ref()
-        .expect("Port object is missing properties");
-    let name = props.get("port.name").unwrap_or_default().to_string();
-    let node_id: u32 = props
-        .get("node.id")
-        .expect("Port has no node.id property!")
-        .parse()
-        .expect("Could not parse node.id property");
-    let direction = if matches!(props.get("port.direction"), Some("in")) {
-        Direction::Input
-    } else {
-        Direction::Output
-    };
-
-    // Find out the nodes media type so that the port can be colored.
-    let media_type = if let Some(Item::Node { media_type, .. }) = state.borrow().get(node_id) {
-        media_type.to_owned()
-    } else {
-        warn!("Node not found for Port {}", port.id);
-        None
-    };
-
-    // Save node_id so we can delete this port easily.
-    state.borrow_mut().insert(port.id, Item::Port { node_id });
-
-    sender
-        .send(PipewireMessage::PortAdded {
-            id: port.id,
-            node_id,
-            name,
-            direction,
-            media_type,
-        })
-        .expect("Failed to send message");
-}
-
-/// Handle a new link being added
-fn handle_link(
-    link: &GlobalObject<ForeignDict>,
-    sender: &glib::Sender<PipewireMessage>,
-    registry: &Rc<Registry>,
-    proxies: &Rc<RefCell<HashMap<u32, ProxyItem>>>,
-    state: &Rc<RefCell<State>>,
-) {
-    debug!(
-        "New link (id:{}) appeared, setting up info listener.",
-        link.id
-    );
-
-    let proxy: Link = registry.bind(link).expect("Failed to bind to link proxy");
-    let listener = proxy
-        .add_listener_local()
-        .info(clone!(@strong state, @strong sender => move |info| {
-            debug!("Received link info: {:?}", info);
-
-            let id = info.id();
-
-            let mut state = state.borrow_mut();
-            if let Some(Item::Link { .. }) = state.get(id) {
-                // Info was an update - figure out if we should notify the gtk thread
-                if info.change_mask().contains(LinkChangeMask::STATE) {
-                    sender.send(PipewireMessage::LinkStateChanged {
-                        id,
-                        active: matches!(info.state(), LinkState::Active)
-                    }).expect("Failed to send message");
-                }
-                // TODO -- check other values that might have changed
-            } else {
-                // First time we get info. We can now notify the gtk thread of a new link.
-                let node_from = info.output_node_id();
-                let port_from = info.output_port_id();
-                let node_to = info.input_node_id();
-                let port_to = info.input_port_id();
-
-                state.insert(id, Item::Link {
-                    port_from, port_to
-                });
-
-                sender.send(PipewireMessage::LinkAdded {
-                    id,
-                    node_from,
-                    port_from,
-                    node_to,
-                    port_to,
-                    active: matches!(info.state(), LinkState::Active)
-                }).expect(
-                    "Failed to send message"
-                );
-            }
-        }))
-        .register();
-
-    proxies.borrow_mut().insert(
-        link.id,
-        ProxyItem::Link {
-            _proxy: proxy,
-            _listener: listener,
-        },
-    );
-}
-
-/// Toggle a link between the two specified ports.
-fn toggle_link(
-    port_from: u32,
-    port_to: u32,
-    core: &Rc<Core>,
-    registry: &Rc<Registry>,
-    state: &Rc<RefCell<State>>,
-) {
-    let state = state.borrow_mut();
-    if let Some(id) = state.get_link_id(port_from, port_to) {
-        info!("Requesting removal of link with id {}", id);
-
-        // FIXME: Handle error
-        registry.destroy_global(id);
-    } else {
-        info!(
-            "Requesting creation of link from port id:{} to port id:{}",
-            port_from, port_to
-        );
-
-        let node_from = state
-            .get_node_of_port(port_from)
-            .expect("Requested port not in state");
-        let node_to = state
-            .get_node_of_port(port_to)
-            .expect("Requested port not in state");
-
-        if let Err(e) = core.create_object::<Link, _>(
-            "link-factory",
-            &properties! {
-                "link.output.node" => node_from.to_string(),
-                "link.output.port" => port_from.to_string(),
-                "link.input.node" => node_to.to_string(),
-                "link.input.port" => port_to.to_string(),
-                "object.linger" => "1"
-            },
-        ) {
-            warn!("Failed to create link: {}", e);
-        }
-    }
-}

src/pipewire_connection/mod.rs

@@ -0,0 +1,525 @@
+// Copyright 2021 Tom A. Wagner <tom.a.wagner@protonmail.com>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License version 3 as published by
+// the Free Software Foundation.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+// SPDX-License-Identifier: GPL-3.0-only
+
+mod state;
+
+use std::{
+    cell::{Cell, RefCell},
+    collections::HashMap,
+    rc::Rc,
+    time::Duration,
+};
+
+use adw::glib::{self, clone};
+use log::{debug, error, info, warn};
+use pipewire::{
+    context::Context,
+    core::{Core, PW_ID_CORE},
+    keys,
+    link::{Link, LinkChangeMask, LinkInfoRef, LinkListener, LinkState},
+    main_loop::MainLoop,
+    node::{Node, NodeInfoRef, NodeListener},
+    port::{Port, PortChangeMask, PortInfoRef, PortListener},
+    properties::properties,
+    registry::{GlobalObject, Registry},
+    spa::{
+        param::{ParamInfoFlags, ParamType},
+        utils::dict::DictRef,
+        utils::result::SpaResult,
+    },
+    types::ObjectType,
+};
+
+use crate::{GtkMessage, MediaType, NodeType, PipewireMessage};
+use state::{Item, State};
+
+enum ProxyItem {
+    Node {
+        _proxy: Node,
+        _listener: NodeListener,
+    },
+    Port {
+        proxy: Port,
+        _listener: PortListener,
+    },
+    Link {
+        _proxy: Link,
+        _listener: LinkListener,
+    },
+}
+
+/// The "main" function of the pipewire thread.
+pub(super) fn thread_main(
+    gtk_sender: async_channel::Sender<PipewireMessage>,
+    mut pw_receiver: pipewire::channel::Receiver<GtkMessage>,
+) {
+    let mainloop = MainLoop::new(None).expect("Failed to create mainloop");
+    let context = Rc::new(Context::new(&mainloop).expect("Failed to create context"));
+    let is_stopped = Rc::new(Cell::new(false));
+    let mut is_connecting = false;
+
+    while !is_stopped.get() {
+        // Try to connect
+        let core = match context.connect(Some(properties! {
+            "media.category" => "Manager"
+        })) {
+            Ok(core) => Rc::new(core),
+            Err(_) => {
+                if !is_connecting {
+                    is_connecting = true;
+                    gtk_sender
+                        .send_blocking(PipewireMessage::Connecting)
+                        .expect("Failed to send message");
+                }
+
+                // If connection is failed, try to connect again in 200ms
+                let interval = Some(Duration::from_millis(200));
+
+                let timer = mainloop
+                    .loop_()
+                    .add_timer(clone!(@strong mainloop => move |_| {
+                        mainloop.quit();
+                    }));
+
+                timer.update_timer(interval, None).into_result().unwrap();
+
+                let receiver = pw_receiver.attach(mainloop.loop_(), {
+                    clone!(@strong mainloop, @strong is_stopped => move |msg|
+                        if let GtkMessage::Terminate = msg {
+                            // main thread requested stop
+                            is_stopped.set(true);
+                            mainloop.quit();
+                        }
+                    )
+                });
+
+                mainloop.run();
+                pw_receiver = receiver.deattach();
+
+                continue;
+            }
+        };
+
+        if is_connecting {
+            is_connecting = false;
+            gtk_sender
+                .send_blocking(PipewireMessage::Connected)
+                .expect("Failed to send message");
+        }
+
+        let registry = Rc::new(core.get_registry().expect("Failed to get registry"));
+
+        // Keep proxies and their listeners alive so that we can receive info events.
+        let proxies = Rc::new(RefCell::new(HashMap::new()));
+        let state = Rc::new(RefCell::new(State::new()));
+
+        let receiver = pw_receiver.attach(mainloop.loop_(), {
+            clone!(@strong mainloop, @weak core, @weak registry, @strong state, @strong is_stopped => move |msg| match msg {
+                GtkMessage::ToggleLink { port_from, port_to } => toggle_link(port_from, port_to, &core, &registry, &state),
+                GtkMessage::Terminate => {
+                    // main thread requested stop
+                    is_stopped.set(true);
+                    mainloop.quit();
+                }
+            })
+        });
+
+        let gtk_sender = gtk_sender.clone();
+        let _listener = core.add_listener_local()
+            .error(clone!(@strong mainloop, @strong gtk_sender, @strong is_stopped => move |id, _seq, res, message| {
+                if id != PW_ID_CORE {
+                    return;
+                }
+
+                if res == -libc::EPIPE {
+                    gtk_sender.send_blocking(PipewireMessage::Disconnected)
+                        .expect("Failed to send message");
+                    mainloop.quit();
+                } else {
+                    let serr = SpaResult::from_c(res).into_result().unwrap_err();
+                    error!("Pipewire Core received error {serr}: {message}");
+                }
+            }))
+            .register();
+
+        let _listener = registry
+            .add_listener_local()
+            .global(clone!(@strong gtk_sender, @weak registry, @strong proxies, @strong state =>
+                move |global| match global.type_ {
+                    ObjectType::Node => handle_node(global, &gtk_sender, &registry, &proxies, &state),
+                    ObjectType::Port => handle_port(global, &gtk_sender, &registry, &proxies, &state),
+                    ObjectType::Link => handle_link(global, &gtk_sender, &registry, &proxies, &state),
+                    _ => {
+                        // Other objects are not interesting to us
+                    }
+                }
+            ))
+            .global_remove(clone!(@strong proxies, @strong state => move |id| {
+                if let Some(item) = state.borrow_mut().remove(id) {
+                    gtk_sender.send_blocking(match item {
+                        Item::Node { .. } => PipewireMessage::NodeRemoved {id},
+                        Item::Port { node_id } => PipewireMessage::PortRemoved {id, node_id},
+                        Item::Link { .. } => PipewireMessage::LinkRemoved {id},
+                    }).expect("Failed to send message");
+                } else {
+                    warn!(
+                        "Attempted to remove item with id {} that is not saved in state",
+                        id
+                    );
+                }
+
+                proxies.borrow_mut().remove(&id);
+            }))
+            .register();
+
+        mainloop.run();
+        pw_receiver = receiver.deattach();
+    }
+}
+
+/// Get the nicest possible name for the node, using a fallback chain of possible name attributes
+fn get_node_name(props: &DictRef) -> &str {
+    props
+        .get(&keys::NODE_DESCRIPTION)
+        .or_else(|| props.get(&keys::NODE_NICK))
+        .or_else(|| props.get(&keys::NODE_NAME))
+        .unwrap_or_default()
+}
+
+/// Handle a new node being added
+fn handle_node(
+    node: &GlobalObject<&DictRef>,
+    sender: &async_channel::Sender<PipewireMessage>,
+    registry: &Rc<Registry>,
+    proxies: &Rc<RefCell<HashMap<u32, ProxyItem>>>,
+    state: &Rc<RefCell<State>>,
+) {
+    let props = node
+        .props
+        .as_ref()
+        .expect("Node object is missing properties");
+
+    let name = get_node_name(props).to_string();
+    let media_class = |class: &str| {
+        if class.contains("Sink") || class.contains("Input") {
+            Some(NodeType::Input)
+        } else if class.contains("Source") || class.contains("Output") {
+            Some(NodeType::Output)
+        } else {
+            None
+        }
+    };
+
+    let node_type = props
+        .get("media.category")
+        .and_then(|class| {
+            if class.contains("Duplex") {
+                None
+            } else {
+                props.get("media.class").and_then(media_class)
+            }
+        })
+        .or_else(|| props.get("media.class").and_then(media_class));
+
+    state.borrow_mut().insert(node.id, Item::Node);
+
+    sender
+        .send_blocking(PipewireMessage::NodeAdded {
+            id: node.id,
+            name,
+            node_type,
+        })
+        .expect("Failed to send message");
+
+    let proxy: Node = registry.bind(node).expect("Failed to bind to node proxy");
+    let listener = proxy
+        .add_listener_local()
+        .info(clone!(@strong sender, @strong proxies => move |info| {
+            handle_node_info(info, &sender, &proxies);
+        }))
+        .register();
+
+    proxies.borrow_mut().insert(
+        node.id,
+        ProxyItem::Node {
+            _proxy: proxy,
+            _listener: listener,
+        },
+    );
+}
+
+fn handle_node_info(
+    info: &NodeInfoRef,
+    sender: &async_channel::Sender<PipewireMessage>,
+    proxies: &Rc<RefCell<HashMap<u32, ProxyItem>>>,
+) {
+    debug!("Received node info: {:?}", info);
+
+    let id = info.id();
+    let proxies = proxies.borrow();
+    let Some(ProxyItem::Node { .. }) = proxies.get(&id) else {
+        error!("Received info on unknown node with id {id}");
+        return;
+    };
+
+    let props = info.props().expect("NodeInfo object is missing properties");
+    if let Some(media_name) = props.get(&keys::MEDIA_NAME) {
+        let name = get_node_name(props).to_string();
+
+        sender
+            .send_blocking(PipewireMessage::NodeNameChanged {
+                id,
+                name,
+                media_name: media_name.to_string(),
+            })
+            .expect("Failed to send message");
+    }
+}
+
+/// Handle a new port being added
+fn handle_port(
+    port: &GlobalObject<&DictRef>,
+    sender: &async_channel::Sender<PipewireMessage>,
+    registry: &Rc<Registry>,
+    proxies: &Rc<RefCell<HashMap<u32, ProxyItem>>>,
+    state: &Rc<RefCell<State>>,
+) {
+    let port_id = port.id;
+    let proxy: Port = registry.bind(port).expect("Failed to bind to port proxy");
+    let listener = proxy
+        .add_listener_local()
+        .info(
+            clone!(@strong proxies, @strong state, @strong sender => move |info| {
+                handle_port_info(info, &proxies, &state, &sender);
+            }),
+        )
+        .param(clone!(@strong sender => move |_, param_id, _, _, param| {
+            if param_id == ParamType::EnumFormat {
+                handle_port_enum_format(port_id, param, &sender)
+            }
+        }))
+        .register();
+
+    proxies.borrow_mut().insert(
+        port.id,
+        ProxyItem::Port {
+            proxy,
+            _listener: listener,
+        },
+    );
+}
+
+fn handle_port_info(
+    info: &PortInfoRef,
+    proxies: &Rc<RefCell<HashMap<u32, ProxyItem>>>,
+    state: &Rc<RefCell<State>>,
+    sender: &async_channel::Sender<PipewireMessage>,
+) {
+    debug!("Received port info: {:?}", info);
+
+    let id = info.id();
+    let proxies = proxies.borrow();
+    let Some(ProxyItem::Port { proxy, .. }) = proxies.get(&id) else {
+        log::error!("Received info on unknown port with id {id}");
+        return;
+    };
+
+    let mut state = state.borrow_mut();
+
+    if let Some(Item::Port { .. }) = state.get(id) {
+        // Info was an update, figure out if we should notify the GTK thread
+        if info.change_mask().contains(PortChangeMask::PARAMS) {
+            // TODO: React to param changes
+        }
+    } else {
+        // First time we get info. We can now notify the gtk thread of a new link.
+        let props = info.props().expect("Port object is missing properties");
+        let name = props.get("port.name").unwrap_or_default().to_string();
+        let node_id: u32 = props
+            .get("node.id")
+            .expect("Port has no node.id property!")
+            .parse()
+            .expect("Could not parse node.id property");
+
+        state.insert(id, Item::Port { node_id });
+
+        let params = info.params();
+        let enum_format_info = params
+            .iter()
+            .find(|param| param.id() == ParamType::EnumFormat);
+        if let Some(enum_format_info) = enum_format_info {
+            if enum_format_info.flags().contains(ParamInfoFlags::READ) {
+                proxy.enum_params(0, Some(ParamType::EnumFormat), 0, u32::MAX);
+            }
+        }
+
+        sender
+            .send_blocking(PipewireMessage::PortAdded {
+                id,
+                node_id,
+                name,
+                direction: info.direction(),
+            })
+            .expect("Failed to send message");
+    }
+}
+
+fn handle_port_enum_format(
+    port_id: u32,
+    param: Option<&pipewire::spa::pod::Pod>,
+    sender: &async_channel::Sender<PipewireMessage>,
+) {
+    let media_type = param
+        .and_then(|param| pipewire::spa::param::format_utils::parse_format(param).ok())
+        .map(|(media_type, _media_subtype)| media_type)
+        .unwrap_or(MediaType::Unknown);
+
+    sender
+        .send_blocking(PipewireMessage::PortFormatChanged {
+            id: port_id,
+            media_type,
+        })
+        .expect("Failed to send message")
+}
+
+/// Handle a new link being added
+fn handle_link(
+    link: &GlobalObject<&DictRef>,
+    sender: &async_channel::Sender<PipewireMessage>,
+    registry: &Rc<Registry>,
+    proxies: &Rc<RefCell<HashMap<u32, ProxyItem>>>,
+    state: &Rc<RefCell<State>>,
+) {
+    debug!(
+        "New link (id:{}) appeared, setting up info listener.",
+        link.id
+    );
+
+    let proxy: Link = registry.bind(link).expect("Failed to bind to link proxy");
+    let listener = proxy
+        .add_listener_local()
+        .info(clone!(@strong state, @strong sender => move |info| {
+            handle_link_info(info, &state, &sender);
+        }))
+        .register();
+
+    proxies.borrow_mut().insert(
+        link.id,
+        ProxyItem::Link {
+            _proxy: proxy,
+            _listener: listener,
+        },
+    );
+}
+
+fn handle_link_info(
+    info: &LinkInfoRef,
+    state: &Rc<RefCell<State>>,
+    sender: &async_channel::Sender<PipewireMessage>,
+) {
+    debug!("Received link info: {:?}", info);
+
+    let id = info.id();
+
+    let mut state = state.borrow_mut();
+    if let Some(Item::Link { .. }) = state.get(id) {
+        // Info was an update - figure out if we should notify the gtk thread
+        if info.change_mask().contains(LinkChangeMask::STATE) {
+            sender
+                .send_blocking(PipewireMessage::LinkStateChanged {
+                    id,
+                    active: matches!(info.state(), LinkState::Active),
+                })
+                .expect("Failed to send message");
+        }
+        if info.change_mask().contains(LinkChangeMask::FORMAT) {
+            sender
+                .send_blocking(PipewireMessage::LinkFormatChanged {
+                    id,
+                    media_type: get_link_media_type(info),
+                })
+                .expect("Failed to send message");
+        }
+    } else {
+        // First time we get info. We can now notify the gtk thread of a new link.
+        let port_from = info.output_port_id();
+        let port_to = info.input_port_id();
+
+        state.insert(id, Item::Link { port_from, port_to });
+
+        sender
+            .send_blocking(PipewireMessage::LinkAdded {
+                id,
+                port_from,
+                port_to,
+                active: matches!(info.state(), LinkState::Active),
+                media_type: get_link_media_type(info),
+            })
+            .expect("Failed to send message");
+    }
+}
+
+/// Toggle a link between the two specified ports.
+fn toggle_link(
+    port_from: u32,
+    port_to: u32,
+    core: &Rc<Core>,
+    registry: &Rc<Registry>,
+    state: &Rc<RefCell<State>>,
+) {
+    let state = state.borrow_mut();
+    if let Some(id) = state.get_link_id(port_from, port_to) {
+        info!("Requesting removal of link with id {}", id);
+
+        // FIXME: Handle error
+        registry.destroy_global(id);
+    } else {
+        info!(
+            "Requesting creation of link from port id:{} to port id:{}",
+            port_from, port_to
+        );
+
+        let node_from = state
+            .get_node_of_port(port_from)
+            .expect("Requested port not in state");
+        let node_to = state
+            .get_node_of_port(port_to)
+            .expect("Requested port not in state");
+
+        if let Err(e) = core.create_object::<Link>(
+            "link-factory",
+            &properties! {
+                "link.output.node" => node_from.to_string(),
+                "link.output.port" => port_from.to_string(),
+                "link.input.node" => node_to.to_string(),
+                "link.input.port" => port_to.to_string(),
+                "object.linger" => "1"
+            },
+        ) {
+            warn!("Failed to create link: {}", e);
+        }
+    }
+}
+
+fn get_link_media_type(link_info: &LinkInfoRef) -> MediaType {
+    let media_type = link_info
+        .format()
+        .and_then(|format| pipewire::spa::param::format_utils::parse_format(format).ok())
+        .map(|(media_type, _media_subtype)| media_type)
+        .unwrap_or(MediaType::Unknown);
+
+    media_type
+}

src/pipewire_connection/state.rs

@@ -16,15 +16,10 @@
 
 use std::collections::HashMap;
 
-use crate::MediaType;
-
 /// Any pipewire item we need to keep track of.
 /// These will be saved in the `State` struct associated with their id.
 pub(super) enum Item {
-    Node {
+    Node,
-        // Keep track of the nodes media type to color ports on it.
-        media_type: Option<MediaType>,
-    },
     Port {
         // Save the id of the node this is on so we can remove the port from it
         // when it is deleted.

src/style.css

@@ -15,26 +15,58 @@
    SPDX-License-Identifier: GPL-3.0-only
 */
 
-@define-color audio rgb(50,100,240);
+@define-color media-type-audio   rgb( 50, 100, 240);
-@define-color video rgb(200,200,0);
+@define-color media-type-video   rgb(200, 200,   0);
-@define-color midi rgb(200,0,50);
+@define-color media-type-midi    rgb(200,   0,  50);
-@define-color graphview-link #808080;
+@define-color media-type-unknown rgb(128, 128, 128);
 
 .audio {
-    background: @audio;
+    background: @media-type-audio;
     color: black;
 }
 
 .video {
-    background: @video;
+    background: @media-type-video;
     color: black;
 }
 
 .midi {
-    background: @midi;
+    background: @media-type-midi;
     color: black;
 }
 
-graphview {
+node {
-    background-color: @text_view_bg;
+    /* Compared to the default card color, this is not transparent in dark-mode
+       and provides a better contrast to the background in light mode */
+	background-color: @headerbar_bg_color;
+}
+
+node .node-title {
+	padding: 4px 7px;
+}
+
+port label {
+    padding: 4px 6px;
+}
+
+port-handle {
+    border-radius: 50%;
+    background-color: @media-type-unknown;
+}
+
+button.rounded {
+    padding: 6px;
+    border-radius: 9999px;
+}
+
+entry.rounded {
+    border-radius: 9999px;
+}
+
+entry.rounded > :first-child {
+    padding-left: 12px;
+}
+
+entry.rounded > :nth-child(2) {
+    padding-right: 12px;
 }

src/ui/graph/graph_view.rs

@@ -14,20 +14,21 @@
 //
 // SPDX-License-Identifier: GPL-3.0-only
 
-use super::{Node, Port};
+use adw::{
-
+    gio,
-use gtk::{
     glib::{self, clone},
-    graphene,
+    gtk::{
-    graphene::Point,
+        self, cairo,
-    gsk,
+        graphene::{self, Point},
+        gsk,
+    },
     prelude::*,
     subclass::prelude::*,
 };
-use log::{error, warn};
 
-use std::{cmp::Ordering, collections::HashMap};
+use std::cmp::Ordering;
 
+use super::{Link, Node, Port};
 use crate::NodeType;
 
 const CANVAS_SIZE: f64 = 5000.0;
@@ -36,14 +37,31 @@ mod imp {
     use super::*;
 
     use std::cell::{Cell, RefCell};
+    use std::collections::{HashMap, HashSet};
 
-    use gtk::{
+    use adw::gtk::gdk::{self};
-        gdk::{self, RGBA},
-        graphene::Rect,
-        gsk::ColorStop,
-    };
     use log::warn;
     use once_cell::sync::Lazy;
+    use pipewire::spa::param::format::MediaType;
+    use pipewire::spa::utils::Direction;
+
+    pub struct Colors {
+        audio: gdk::RGBA,
+        video: gdk::RGBA,
+        midi: gdk::RGBA,
+        unknown: gdk::RGBA,
+    }
+
+    impl Colors {
+        pub fn color_for_media_type(&self, media_type: MediaType) -> &gdk::RGBA {
+            match media_type {
+                MediaType::Audio => &self.audio,
+                MediaType::Video => &self.video,
+                MediaType::Stream | MediaType::Application => &self.midi,
+                _ => &self.unknown,
+            }
+        }
+    }
 
     pub struct DragState {
         node: glib::WeakRef<Node>,
@@ -54,25 +72,53 @@ mod imp {
         offset: Point,
     }
 
-    #[derive(Default)]
     pub struct GraphView {
         /// Stores nodes and their positions.
-        pub(super) nodes: RefCell<HashMap<u32, (Node, Point)>>,
+        pub(super) nodes: RefCell<HashMap<Node, Point>>,
-        /// Stores the link and whether it is currently active.
+        /// Stores the links and whether they are currently active.
-        pub(super) links: RefCell<HashMap<u32, (crate::PipewireLink, bool)>>,
+        pub(super) links: RefCell<HashSet<Link>>,
+
+        // Properties for zooming and scrolling the hraph
         pub hadjustment: RefCell<Option<gtk::Adjustment>>,
         pub vadjustment: RefCell<Option<gtk::Adjustment>>,
         pub zoom_factor: Cell<f64>,
+
         /// This keeps track of an ongoing node drag operation.
         pub dragged_node: RefCell<Option<DragState>>,
+
+        // These keep track of an ongoing port drag operation
+        pub dragged_port: glib::WeakRef<Port>,
+        pub port_drag_cursor: Cell<Point>,
+
         // Memorized data for an in-progress zoom gesture
         pub zoom_gesture_initial_zoom: Cell<Option<f64>>,
         pub zoom_gesture_anchor: Cell<Option<(f64, f64)>>,
+
+        // This keeps track of an ongoing move view gesture.
+        pub move_view_state: Cell<(f64, f64)>,
+    }
+
+    impl Default for GraphView {
+        fn default() -> Self {
+            Self {
+                nodes: Default::default(),
+                links: Default::default(),
+                hadjustment: Default::default(),
+                vadjustment: Default::default(),
+                zoom_factor: Default::default(),
+                dragged_node: Default::default(),
+                dragged_port: Default::default(),
+                port_drag_cursor: Cell::new(Point::new(0.0, 0.0)),
+                zoom_gesture_initial_zoom: Default::default(),
+                zoom_gesture_anchor: Default::default(),
+                move_view_state: Default::default(),
+            }
+        }
     }
 
     #[glib::object_subclass]
     impl ObjectSubclass for GraphView {
-        const NAME: &'static str = "GraphView";
+        const NAME: &'static str = "HelvumGraphView";
         type Type = super::GraphView;
         type ParentType = gtk::Widget;
         type Interfaces = (gtk::Scrollable,);
@@ -86,17 +132,21 @@ mod imp {
         fn constructed(&self) {
             self.parent_constructed();
 
+            self.obj().add_css_class("view");
+
             self.obj().set_overflow(gtk::Overflow::Hidden);
 
             self.setup_node_dragging();
+            self.setup_port_drag_and_drop();
             self.setup_scroll_zooming();
             self.setup_zoom_gesture();
+            self.setup_move_view();
         }
 
         fn dispose(&self) {
             self.nodes
                 .borrow()
-                .values()
+                .iter()
                 .for_each(|(node, _)| node.unparent())
         }
 
@@ -153,9 +203,7 @@ mod imp {
         fn size_allocate(&self, _width: i32, _height: i32, baseline: i32) {
             let widget = &*self.obj();
 
-            let zoom_factor = self.zoom_factor.get();
+            for (node, point) in self.nodes.borrow().iter() {
-
-            for (node, point) in self.nodes.borrow().values() {
                 let (_, natural_size) = node.preferred_size();
 
                 let transform = self
@@ -163,8 +211,8 @@ mod imp {
                     .translate(point);
 
                 node.allocate(
-                    (natural_size.width() as f64 / zoom_factor).ceil() as i32,
+                    natural_size.width(),
-                    (natural_size.height() as f64 / zoom_factor).ceil() as i32,
+                    natural_size.height(),
                     baseline,
                     Some(transform),
                 );
@@ -182,12 +230,10 @@ mod imp {
             let widget = &*self.obj();
             let alloc = widget.allocation();
 
-            self.snapshot_background(widget, snapshot);
-
             // Draw all visible children
             self.nodes
                 .borrow()
-                .values()
+                .iter()
                 // Cull nodes from rendering when they are outside the visible canvas area
                 .filter(|(node, _)| alloc.intersect(&node.allocation()).is_some())
                 .for_each(|(node, _)| widget.snapshot_child(node, snapshot));
@@ -247,7 +293,9 @@ mod imp {
                     // Drag the Node around the screen.
                     let node = target.dynamic_cast_ref::<Node>().unwrap();
 
-                    let Some(canvas_node_pos) = widget.node_position(node) else { return };
+                    let Some(canvas_node_pos) = widget.node_position(node) else {
+                        return;
+                    };
                     let canvas_cursor_pos = widget
                         .imp()
                         .screen_space_to_canvas_space_transform()
@@ -270,7 +318,9 @@ mod imp {
                     .dynamic_cast::<super::GraphView>()
                     .expect("drag-update event is not on the GraphView");
                 let dragged_node = widget.imp().dragged_node.borrow();
-                let Some(DragState { node, offset }) = dragged_node.as_ref() else { return };
+                let Some(DragState { node, offset }) = dragged_node.as_ref() else {
+                    return;
+                };
                 let Some(node) = node.upgrade() else { return };
 
                 let (start_x, start_y) = drag_controller
@@ -292,6 +342,78 @@ mod imp {
             self.obj().add_controller(drag_controller);
         }
 
+        fn setup_port_drag_and_drop(&self) {
+            let controller = gtk::DropControllerMotion::new();
+
+            controller.connect_enter(|controller, x, y| {
+                let graph = controller
+                    .widget()
+                    .downcast::<super::GraphView>()
+                    .expect("Widget should be a graphview");
+
+                graph.imp().port_drag_enter(controller, x, y)
+            });
+
+            controller.connect_motion(|controller, x, y| {
+                let graph = controller
+                    .widget()
+                    .downcast::<super::GraphView>()
+                    .expect("Widget should be a graphview");
+
+                graph.imp().port_drag_motion(x, y)
+            });
+
+            controller.connect_leave(|controller| {
+                let graph = controller
+                    .widget()
+                    .downcast::<super::GraphView>()
+                    .expect("Widget should be a graphview");
+
+                graph.imp().port_drag_leave()
+            });
+
+            self.obj().add_controller(controller);
+        }
+
+        fn port_drag_enter(&self, controller: &gtk::DropControllerMotion, x: f64, y: f64) {
+            let Some(drop) = controller.drop() else {
+                return;
+            };
+
+            self.port_drag_cursor.set(Point::new(x as f32, y as f32));
+
+            drop.read_value_async(
+                Port::static_type(),
+                glib::Priority::DEFAULT,
+                Option::<&gio::Cancellable>::None,
+                clone!(@weak self as imp => move|value| {
+                    let Ok(value) = value else {
+                        return;
+                    };
+                    let port: &Port = value.get().expect("Value should contain a port");
+
+                    imp.dragged_port.set(Some(port));
+                }),
+            );
+
+            self.obj().queue_draw();
+        }
+
+        fn port_drag_motion(&self, x: f64, y: f64) {
+            if self.dragged_port.upgrade().is_some() {
+                self.port_drag_cursor.set(Point::new(x as f32, y as f32));
+
+                self.obj().queue_draw();
+            }
+        }
+
+        fn port_drag_leave(&self) {
+            if self.dragged_port.upgrade().is_some() {
+                self.dragged_port.set(None);
+                self.obj().queue_draw();
+            }
+        }
+
         fn setup_scroll_zooming(&self) {
             // We're only interested in the vertical axis, but for devices like touchpads,
             // not capturing a small accidental horizontal move may cause the scroll to be disrupted if a widget
@@ -312,9 +434,9 @@ mod imp {
                         .unwrap();
                     widget.set_zoom_factor(widget.zoom_factor() + (0.1 * -delta_y), None);
 
-                    gtk::Inhibit(true)
+                    glib::Propagation::Stop
                 } else {
-                    gtk::Inhibit(false)
+                    glib::Propagation::Proceed
                 }
             });
             self.obj().add_controller(scroll_controller);
@@ -348,165 +470,190 @@ mod imp {
             self.obj().add_controller(zoom_gesture);
         }
 
-        fn snapshot_background(&self, widget: &super::GraphView, snapshot: &gtk::Snapshot) {
+        fn setup_move_view(&self) {
-            // Grid size and line width during neutral zoom (factor 1.0).
+            let drag_controller = gtk::GestureDrag::new();
-            const NORMAL_GRID_SIZE: f32 = 20.0;
-            const NORMAL_GRID_LINE_WIDTH: f32 = 1.0;
 
-            let zoom_factor = self.zoom_factor.get();
+            drag_controller.set_button(gtk::gdk::BUTTON_MIDDLE);
-            let grid_size = NORMAL_GRID_SIZE * zoom_factor as f32;
-            let grid_line_width = NORMAL_GRID_LINE_WIDTH * zoom_factor as f32;
 
-            let alloc = widget.allocation();
+            // TODO: set `all-scroll` cursor while dragging view
 
-            // We need to offset the lines between 0 and (excluding) `grid_size` so the grid moves with
+            drag_controller.connect_drag_begin(|drag_controller, _, _| {
-            // the rest of the view when scrolling.
+                let widget = drag_controller
-            // The offset is rounded so the grid is always aligned to a row of pixels.
+                    .widget()
-            let hadj = self
+                    .downcast::<super::GraphView>()
-                .hadjustment
+                    .unwrap();
-                .borrow()
-                .as_ref()
-                .map(|hadjustment| hadjustment.value())
-                .unwrap_or(0.0);
-            let hoffset = (grid_size - (hadj as f32 % grid_size)) % grid_size;
-            let vadj = self
-                .vadjustment
-                .borrow()
-                .as_ref()
-                .map(|vadjustment| vadjustment.value())
-                .unwrap_or(0.0);
-            let voffset = (grid_size - (vadj as f32 % grid_size)) % grid_size;
 
-            snapshot.push_repeat(
+                widget.imp().move_view_state.set((0.0, 0.0));
-                &Rect::new(0.0, 0.0, alloc.width() as f32, alloc.height() as f32),
+            });
-                Some(&Rect::new(0.0, voffset, alloc.width() as f32, grid_size)),
+
+            drag_controller.connect_drag_update(|drag_controller, x, y| {
+                let widget = drag_controller
+                    .widget()
+                    .downcast::<super::GraphView>()
+                    .unwrap();
+
+                let imp = widget.imp();
+                let state = imp.move_view_state.replace((x, y));
+                let delta_x = state.0 - x;
+                let delta_y = state.1 - y;
+
+                let hadjustment_ref = imp.hadjustment.borrow();
+                let vadjustment_ref = imp.vadjustment.borrow();
+                let hadjustment = hadjustment_ref.as_ref().unwrap();
+                let vadjustment = vadjustment_ref.as_ref().unwrap();
+
+                let new_hadjustment = hadjustment.value() + delta_x;
+                let new_vadjustment = vadjustment.value() + delta_y;
+
+                hadjustment.set_value(new_hadjustment);
+                vadjustment.set_value(new_vadjustment);
+            });
+
+            self.obj().add_controller(drag_controller);
+        }
+
+        fn snapshot_link(
+            &self,
+            snapshot: &gtk::Snapshot,
+            output_anchor: &Point,
+            input_anchor: &Point,
+            active: bool,
+            color: &gdk::RGBA,
+        ) {
+            let output_x = output_anchor.x();
+            let output_y = output_anchor.y();
+            let input_x = input_anchor.x();
+            let input_y = input_anchor.y();
+
+            // If the output port is farther right than the input port and they have
+            // a similar y coordinate, apply a y offset to the control points
+            // so that the curve sticks out a bit.
+            let y_control_offset = if output_x > input_x {
+                f32::max(0.0, 25.0 - (output_y - input_y).abs())
+            } else {
+                0.0
+            };
+
+            // Place curve control offset by half the x distance between the two points.
+            // This makes the curve scale well for varying distances between the two ports,
+            // especially when the output port is farther right than the input port.
+            let half_x_dist = f32::abs(output_x - input_x) / 2.0;
+            let path_builder = gsk::PathBuilder::new();
+            path_builder.move_to(output_x, output_y);
+            path_builder.cubic_to(
+                output_x + half_x_dist,
+                output_y - y_control_offset,
+                input_x - half_x_dist,
+                input_y - y_control_offset,
+                input_x,
+                input_y,
             );
-            let grid_color = RGBA::new(0.137, 0.137, 0.137, 1.0);
+            let path = path_builder.to_path();
-            snapshot.append_linear_gradient(
-                &Rect::new(0.0, voffset, alloc.width() as f32, grid_line_width),
-                &Point::new(0.0, 0.0),
-                &Point::new(alloc.width() as f32, 0.0),
-                &[
-                    ColorStop::new(0.0, grid_color),
-                    ColorStop::new(1.0, grid_color),
-                ],
-            );
-            snapshot.pop();
 
-            snapshot.push_repeat(
+            let stroke = gsk::Stroke::new(2.0 * (self.zoom_factor.get() as f32));
-                &Rect::new(0.0, 0.0, alloc.width() as f32, alloc.height() as f32),
+            // Use dashed line for inactive links, full line otherwise.
-                Some(&Rect::new(hoffset, 0.0, grid_size, alloc.height() as f32)),
+            if active {
-            );
+                stroke.set_dash(&[]);
-            snapshot.append_linear_gradient(
+            } else {
-                &Rect::new(hoffset, 0.0, grid_line_width, alloc.height() as f32),
+                stroke.set_dash(&[10.0, 5.0]);
-                &Point::new(0.0, 0.0),
+            }
-                &Point::new(0.0, alloc.height() as f32),
+
-                &[
+            snapshot.append_stroke(&path, &stroke, color);
-                    ColorStop::new(0.0, grid_color),
+        }
-                    ColorStop::new(1.0, grid_color),
+
-                ],
+        fn snapshot_dragged_link(&self, snapshot: &gtk::Snapshot, port: &Port, colors: &Colors) {
-            );
+            let Some(port_anchor) = port.compute_point(&*self.obj(), &port.link_anchor()) else {
-            snapshot.pop();
+                return;
+            };
+            let drag_cursor = self.port_drag_cursor.get();
+
+            /* If we can find a linkable port under the cursor, link to its anchor,
+             * otherwise link to the mouse cursor */
+            let picked_port = self
+                .obj()
+                .pick(
+                    drag_cursor.x().into(),
+                    drag_cursor.y().into(),
+                    gtk::PickFlags::DEFAULT,
+                )
+                .and_then(|widget| widget.ancestor(Port::static_type()).and_downcast::<Port>())
+                .filter(|picked_port| port.is_linkable_to(picked_port));
+            let picked_port_anchor = picked_port.and_then(|picked_port| {
+                picked_port.compute_point(&*self.obj(), &picked_port.link_anchor())
+            });
+            let other_anchor = picked_port_anchor.unwrap_or(drag_cursor);
+
+            let (output_anchor, input_anchor) = match Direction::from_raw(port.direction()) {
+                Direction::Output => (&port_anchor, &other_anchor),
+                Direction::Input => (&other_anchor, &port_anchor),
+                _ => unreachable!(),
+            };
+
+            let color = &colors.color_for_media_type(MediaType::from_raw(port.media_type()));
+
+            self.snapshot_link(snapshot, output_anchor, input_anchor, false, color);
         }
 
         fn snapshot_links(&self, widget: &super::GraphView, snapshot: &gtk::Snapshot) {
-            let alloc = widget.allocation();
+            let colors = Colors {
+                audio: widget
+                    .style_context()
+                    .lookup_color("media-type-audio")
+                    .expect("color not found"),
+                video: widget
+                    .style_context()
+                    .lookup_color("media-type-video")
+                    .expect("color not found"),
+                midi: widget
+                    .style_context()
+                    .lookup_color("media-type-midi")
+                    .expect("color not found"),
+                unknown: widget
+                    .style_context()
+                    .lookup_color("media-type-unknown")
+                    .expect("color not found"),
+            };
 
-            let link_cr = snapshot.append_cairo(&graphene::Rect::new(
+            for link in self.links.borrow().iter() {
-                0.0,
+                let color = &colors.color_for_media_type(link.media_type());
-                0.0,
-                alloc.width() as f32,
-                alloc.height() as f32,
-            ));
 
-            link_cr.set_line_width(2.0 * self.zoom_factor.get());
-
-            let rgba = widget
-                .style_context()
-                .lookup_color("graphview-link")
-                .unwrap_or(gtk::gdk::RGBA::BLACK);
-
-            link_cr.set_source_rgba(
-                rgba.red().into(),
-                rgba.green().into(),
-                rgba.blue().into(),
-                rgba.alpha().into(),
-            );
-
-            for (link, active) in self.links.borrow().values() {
                 // TODO: Do not draw links when they are outside the view
-                if let Some((from_x, from_y, to_x, to_y)) = self.get_link_coordinates(link) {
+                let Some((output_anchor, input_anchor)) = self.get_link_coordinates(link) else {
-                    link_cr.move_to(from_x, from_y);
-
-                    // Use dashed line for inactive links, full line otherwise.
-                    if *active {
-                        link_cr.set_dash(&[], 0.0);
-                    } else {
-                        link_cr.set_dash(&[10.0, 5.0], 0.0);
-                    }
-
-                    // If the output port is farther right than the input port and they have
-                    // a similar y coordinate, apply a y offset to the control points
-                    // so that the curve sticks out a bit.
-                    let y_control_offset = if from_x > to_x {
-                        f64::max(0.0, 25.0 - (from_y - to_y).abs())
-                    } else {
-                        0.0
-                    };
-
-                    // Place curve control offset by half the x distance between the two points.
-                    // This makes the curve scale well for varying distances between the two ports,
-                    // especially when the output port is farther right than the input port.
-                    let half_x_dist = f64::abs(from_x - to_x) / 2.0;
-                    link_cr.curve_to(
-                        from_x + half_x_dist,
-                        from_y - y_control_offset,
-                        to_x - half_x_dist,
-                        to_y - y_control_offset,
-                        to_x,
-                        to_y,
-                    );
-
-                    if let Err(e) = link_cr.stroke() {
-                        warn!("Failed to draw graphview links: {}", e);
-                    };
-                } else {
                     warn!("Could not get allocation of ports of link: {:?}", link);
-                }
+                    continue;
+                };
+
+                self.snapshot_link(
+                    snapshot,
+                    &output_anchor,
+                    &input_anchor,
+                    link.active(),
+                    color,
+                );
+            }
+
+            if let Some(port) = self.dragged_port.upgrade() {
+                self.snapshot_dragged_link(&snapshot, &port, &colors);
             }
         }
 
         /// Get coordinates for the drawn link to start at and to end at.
         ///
         /// # Returns
-        /// `Some((from_x, from_y, to_x, to_y))` if all objects the links refers to exist as widgets.
+        /// `Some((output_anchor, input_anchor))` if all objects the links refers to exist as widgets
-        fn get_link_coordinates(&self, link: &crate::PipewireLink) -> Option<(f64, f64, f64, f64)> {
+        /// and those widgets are contained by the graph.
+        ///
+        /// The returned coordinates are in screen-space of the graph.
+        fn get_link_coordinates(&self, link: &Link) -> Option<(graphene::Point, graphene::Point)> {
             let widget = &*self.obj();
-            let nodes = self.nodes.borrow();
 
-            let output_port = &nodes.get(&link.node_from)?.0.get_port(link.port_from)?;
+            let output_port = link.output_port()?;
+            let output_anchor = output_port.compute_point(widget, &output_port.link_anchor())?;
 
-            let output_port_padding =
+            let input_port = link.input_port()?;
-                (output_port.allocated_width() - output_port.width()) as f64 / 2.0;
+            let input_anchor = input_port.compute_point(widget, &input_port.link_anchor())?;
 
-            let (from_x, from_y) = output_port.translate_coordinates(
+            Some((output_anchor, input_anchor))
-                widget,
-                output_port.width() as f64 + output_port_padding,
-                (output_port.height() / 2) as f64,
-            )?;
-
-            let input_port = &nodes.get(&link.node_to)?.0.get_port(link.port_to)?;
-
-            let input_port_padding =
-                (input_port.allocated_width() - input_port.width()) as f64 / 2.0;
-
-            let (to_x, to_y) = input_port.translate_coordinates(
-                widget,
-                -input_port_padding,
-                (input_port.height() / 2) as f64,
-            )?;
-
-            Some((from_x, from_y, to_x, to_y))
         }
 
         fn set_adjustment(
@@ -609,7 +756,7 @@ impl GraphView {
         self.set_property("zoom-factor", zoom_factor);
     }
 
-    pub fn add_node(&self, id: u32, node: Node, node_type: Option<NodeType>) {
+    pub fn add_node(&self, node: Node, node_type: Option<NodeType>) {
         let imp = self.imp();
         node.set_parent(self);
 
@@ -626,7 +773,7 @@ impl GraphView {
         let y = imp
             .nodes
             .borrow()
-            .values()
+            .iter()
             .map(|node| {
                 // Map nodes to their locations
                 let point = self.node_position(&node.0.clone().upcast()).unwrap();
@@ -642,57 +789,48 @@ impl GraphView {
             })
             .map_or(20_f32, |(_x, y)| y + 120.0);
 
-        imp.nodes.borrow_mut().insert(id, (node, Point::new(x, y)));
+        imp.nodes.borrow_mut().insert(node, Point::new(x, y));
     }
 
-    pub fn remove_node(&self, id: u32) {
+    pub fn remove_node(&self, node: &Node) {
         let mut nodes = self.imp().nodes.borrow_mut();
-        if let Some((node, _)) = nodes.remove(&id) {
+
+        if nodes.remove(node).is_some() {
             node.unparent();
         } else {
-            warn!("Tried to remove non-existant node (id={}) from graph", id);
+            log::warn!("Tried to remove non-existant node widget from graph");
         }
     }
 
-    pub fn add_port(&self, node_id: u32, port_id: u32, port: crate::view::port::Port) {
+    pub fn add_link(&self, link: Link) {
-        if let Some((node, _)) = self.imp().nodes.borrow_mut().get_mut(&node_id) {
+        link.connect_notify_local(
-            node.add_port(port_id, port);
+            Some("active"),
-        } else {
+            glib::clone!(@weak self as graph => move |_, _| {
-            error!(
+                graph.queue_draw();
-                "Node with id {} not found when trying to add port with id {} to graph",
+            }),
-                node_id, port_id
+        );
-            );
+        link.connect_notify_local(
-        }
+            Some("media-type"),
-    }
+            glib::clone!(@weak self as graph => move |_, _| {
-
+                graph.queue_draw();
-    pub fn remove_port(&self, id: u32, node_id: u32) {
+            }),
-        let nodes = self.imp().nodes.borrow();
+        );
-        if let Some((node, _)) = nodes.get(&node_id) {
+        self.imp().links.borrow_mut().insert(link);
-            node.remove_port(id);
-        }
-    }
-
-    pub fn add_link(&self, link_id: u32, link: crate::PipewireLink, active: bool) {
-        self.imp()
-            .links
-            .borrow_mut()
-            .insert(link_id, (link, active));
         self.queue_draw();
     }
 
-    pub fn set_link_state(&self, link_id: u32, active: bool) {
+    pub fn remove_link(&self, link: &Link) {
-        if let Some((_, state)) = self.imp().links.borrow_mut().get_mut(&link_id) {
+        let mut links = self.imp().links.borrow_mut();
-            *state = active;
+        links.remove(link);
-            self.queue_draw();
+
-        } else {
+        self.queue_draw();
-            warn!("Link state changed on unknown link (id={})", link_id);
-        }
     }
 
-    pub fn remove_link(&self, id: u32) {
+    pub fn clear(&mut self) {
-        let mut links = self.imp().links.borrow_mut();
+        self.imp().links.borrow_mut().clear();
-        links.remove(&id);
+        for (node, _) in self.imp().nodes.borrow_mut().drain() {
-
+            node.unparent();
+        }
         self.queue_draw();
     }
 
@@ -700,30 +838,22 @@ impl GraphView {
     ///
     /// The returned position is in canvas-space (non-zoomed, (0, 0) fixed in the middle of the canvas).
     pub(super) fn node_position(&self, node: &Node) -> Option<Point> {
-        self.imp()
+        self.imp().nodes.borrow().get(node).copied()
-            .nodes
-            .borrow()
-            .get(&node.pipewire_id())
-            .map(|(_, point)| *point)
     }
 
     pub(super) fn move_node(&self, widget: &Node, point: &Point) {
         let mut nodes = self.imp().nodes.borrow_mut();
-        let mut node = nodes
+        let node_point = nodes.get_mut(widget).expect("Node is not on the graph");
-            .get_mut(&widget.pipewire_id())
-            .expect("Node is not on the graph");
 
         // Clamp the new position to within the graph, so a node can't be moved outside it and be lost.
-        node.1 = Point::new(
+        node_point.set_x(point.x().clamp(
-            point.x().clamp(
+            -(CANVAS_SIZE / 2.0) as f32,
-                -(CANVAS_SIZE / 2.0) as f32,
+            (CANVAS_SIZE / 2.0) as f32 - widget.width() as f32,
-                (CANVAS_SIZE / 2.0) as f32 - widget.width() as f32,
+        ));
-            ),
+        node_point.set_y(point.y().clamp(
-            point.y().clamp(
+            -(CANVAS_SIZE / 2.0) as f32,
-                -(CANVAS_SIZE / 2.0) as f32,
+            (CANVAS_SIZE / 2.0) as f32 - widget.height() as f32,
-                (CANVAS_SIZE / 2.0) as f32 - widget.height() as f32,
+        ));
-            ),
-        );
 
         self.queue_allocate();
     }

src/ui/graph/link.rs

@@ -0,0 +1,148 @@
+// Copyright 2021 Tom A. Wagner <tom.a.wagner@protonmail.com>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License version 3 as published by
+// the Free Software Foundation.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+// SPDX-License-Identifier: GPL-3.0-only
+
+use adw::{glib, prelude::*, subclass::prelude::*};
+use pipewire::spa::param::format::MediaType;
+
+use super::Port;
+
+mod imp {
+    use super::*;
+
+    use std::cell::Cell;
+
+    use once_cell::sync::Lazy;
+
+    pub struct Link {
+        pub output_port: glib::WeakRef<Port>,
+        pub input_port: glib::WeakRef<Port>,
+        pub active: Cell<bool>,
+        pub media_type: Cell<MediaType>,
+    }
+
+    impl Default for Link {
+        fn default() -> Self {
+            Self {
+                output_port: glib::WeakRef::default(),
+                input_port: glib::WeakRef::default(),
+                active: Cell::default(),
+                media_type: Cell::new(MediaType::Unknown),
+            }
+        }
+    }
+
+    #[glib::object_subclass]
+    impl ObjectSubclass for Link {
+        const NAME: &'static str = "HelvumLink";
+        type Type = super::Link;
+        type ParentType = glib::Object;
+    }
+
+    impl ObjectImpl for Link {
+        fn properties() -> &'static [glib::ParamSpec] {
+            static PROPERTIES: Lazy<Vec<glib::ParamSpec>> = Lazy::new(|| {
+                vec![
+                    glib::ParamSpecObject::builder::<Port>("output-port")
+                        .flags(glib::ParamFlags::READWRITE)
+                        .build(),
+                    glib::ParamSpecObject::builder::<Port>("input-port")
+                        .flags(glib::ParamFlags::READWRITE)
+                        .build(),
+                    glib::ParamSpecBoolean::builder("active")
+                        .default_value(false)
+                        .flags(glib::ParamFlags::READWRITE)
+                        .build(),
+                    glib::ParamSpecUInt::builder("media-type")
+                        .default_value(MediaType::Unknown.as_raw())
+                        .flags(glib::ParamFlags::READWRITE)
+                        .build(),
+                ]
+            });
+
+            PROPERTIES.as_ref()
+        }
+
+        fn property(&self, _id: usize, pspec: &glib::ParamSpec) -> glib::Value {
+            match pspec.name() {
+                "output-port" => self.output_port.upgrade().to_value(),
+                "input-port" => self.input_port.upgrade().to_value(),
+                "active" => self.active.get().to_value(),
+                "media-type" => self.media_type.get().as_raw().to_value(),
+                _ => unimplemented!(),
+            }
+        }
+
+        fn set_property(&self, _id: usize, value: &glib::Value, pspec: &glib::ParamSpec) {
+            match pspec.name() {
+                "output-port" => self.output_port.set(value.get().unwrap()),
+                "input-port" => self.input_port.set(value.get().unwrap()),
+                "active" => self.active.set(value.get().unwrap()),
+                "media-type" => self
+                    .media_type
+                    .set(MediaType::from_raw(value.get().unwrap())),
+                _ => unimplemented!(),
+            }
+        }
+    }
+}
+
+glib::wrapper! {
+    pub struct Link(ObjectSubclass<imp::Link>);
+}
+
+impl Link {
+    pub fn new() -> Self {
+        glib::Object::new()
+    }
+
+    pub fn output_port(&self) -> Option<Port> {
+        self.property("output-port")
+    }
+
+    pub fn set_output_port(&self, port: Option<&Port>) {
+        self.set_property("output-port", port);
+    }
+
+    pub fn input_port(&self) -> Option<Port> {
+        self.property("input-port")
+    }
+
+    pub fn set_input_port(&self, port: Option<&Port>) {
+        self.set_property("input-port", port);
+    }
+
+    pub fn active(&self) -> bool {
+        self.property("active")
+    }
+
+    pub fn set_active(&self, active: bool) {
+        self.set_property("active", active);
+    }
+
+    pub fn media_type(&self) -> MediaType {
+        MediaType::from_raw(self.property("media-type"))
+    }
+
+    pub fn set_media_type(&self, media_type: MediaType) {
+        self.set_property("media-type", media_type.as_raw())
+    }
+}
+
+impl Default for Link {
+    fn default() -> Self {
+        Self::new()
+    }
+}

src/ui/graph/mod.rs

@@ -0,0 +1,28 @@
+// Copyright 2021 Tom A. Wagner <tom.a.wagner@protonmail.com>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License version 3 as published by
+// the Free Software Foundation.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+// SPDX-License-Identifier: GPL-3.0-only
+
+mod graph_view;
+pub use graph_view::*;
+mod node;
+pub use node::*;
+mod port;
+pub use port::*;
+mod port_handle;
+pub use port_handle::*;
+mod link;
+pub use link::*;
+mod zoomentry;
+pub use zoomentry::*;

src/ui/graph/node.rs

@@ -0,0 +1,177 @@
+// Copyright 2021 Tom A. Wagner <tom.a.wagner@protonmail.com>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License version 3 as published by
+// the Free Software Foundation.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+// SPDX-License-Identifier: GPL-3.0-only
+
+use adw::{glib, gtk, prelude::*, subclass::prelude::*};
+use pipewire::spa::utils::Direction;
+
+use super::Port;
+
+mod imp {
+    use super::*;
+
+    use std::{
+        cell::{Cell, RefCell},
+        collections::HashSet,
+    };
+
+    #[derive(glib::Properties, gtk::CompositeTemplate, Default)]
+    #[properties(wrapper_type = super::Node)]
+    #[template(file = "node.ui")]
+    pub struct Node {
+        #[property(get, set, construct_only)]
+        pub(super) pipewire_id: Cell<u32>,
+        #[property(
+            name = "node-name", type = String,
+            get = |this: &Self| this.node_name.text().to_string(),
+            set = |this: &Self, val| {
+                this.node_name.set_text(val);
+                this.node_name.set_tooltip_text(Some(val));
+            }
+        )]
+        #[template_child]
+        pub(super) node_name: TemplateChild<gtk::Label>,
+        #[property(
+            name = "media-name", type = String,
+            get = |this: &Self| this.media_name.text().to_string(),
+            set = |this: &Self, val| {
+                this.media_name.set_text(val);
+                this.media_name.set_tooltip_text(Some(val));
+                this.media_name.set_visible(!val.is_empty());
+            }
+        )]
+        #[template_child]
+        pub(super) media_name: TemplateChild<gtk::Label>,
+        #[template_child]
+        pub(super) separator: TemplateChild<gtk::Separator>,
+        #[template_child]
+        pub(super) port_grid: TemplateChild<gtk::Grid>,
+        pub(super) ports: RefCell<HashSet<Port>>,
+    }
+
+    #[glib::object_subclass]
+    impl ObjectSubclass for Node {
+        const NAME: &'static str = "HelvumNode";
+        type Type = super::Node;
+        type ParentType = gtk::Widget;
+
+        fn class_init(klass: &mut Self::Class) {
+            klass.set_layout_manager_type::<gtk::BoxLayout>();
+
+            klass.bind_template();
+
+            klass.set_css_name("node");
+        }
+
+        fn instance_init(obj: &glib::subclass::InitializingObject<Self>) {
+            obj.init_template();
+        }
+    }
+
+    #[glib::derived_properties]
+    impl ObjectImpl for Node {
+        fn constructed(&self) {
+            self.parent_constructed();
+
+            // Force left-to-right direction for the ports grid to avoid messed up UI when defaulting to right-to-left
+            self.port_grid.set_direction(gtk::TextDirection::Ltr);
+
+            // Display a grab cursor when the mouse is over the label so the user knows the node can be dragged.
+            self.node_name
+                .set_cursor(gtk::gdk::Cursor::from_name("grab", None).as_ref());
+        }
+
+        fn dispose(&self) {
+            if let Some(child) = self.obj().first_child() {
+                child.unparent();
+            }
+        }
+    }
+
+    impl WidgetImpl for Node {}
+
+    impl Node {
+        /// Update the internal ports grid to reflect the ports stored in the ports set.
+        pub fn update_ports(&self) {
+            // We first remove all ports from the grid, then re-add them all, so that
+            // ports that have been removed do not leave gaps in the grid.
+
+            while let Some(ref child) = self.port_grid.first_child() {
+                self.port_grid.remove(child);
+            }
+
+            let ports = self.ports.borrow();
+
+            let mut ports_out = Vec::new();
+            let mut ports_in = Vec::new();
+
+            ports
+                .iter()
+                .for_each(|port| match Direction::from_raw(port.direction()) {
+                    Direction::Output => {
+                        ports_out.push(port);
+                    }
+                    Direction::Input => {
+                        ports_in.push(port);
+                    }
+                    _ => unreachable!(),
+                });
+
+            ports_out.sort_unstable_by_key(|port| port.name());
+            ports_in.sort_unstable_by_key(|port| port.name());
+
+            // In case no ports have been added to the port, hide the seperator as it is not needed
+            self.separator
+                .set_visible(!ports_out.is_empty() || !ports_in.is_empty());
+
+            for (i, port) in ports_in.into_iter().enumerate() {
+                self.port_grid.attach(port, 0, i.try_into().unwrap(), 1, 1);
+            }
+
+            for (i, port) in ports_out.into_iter().enumerate() {
+                self.port_grid.attach(port, 1, i.try_into().unwrap(), 1, 1);
+            }
+        }
+    }
+}
+
+glib::wrapper! {
+    pub struct Node(ObjectSubclass<imp::Node>)
+        @extends gtk::Widget;
+}
+
+impl Node {
+    pub fn new(name: &str, pipewire_id: u32) -> Self {
+        glib::Object::builder()
+            .property("node-name", name)
+            .property("pipewire-id", pipewire_id)
+            .build()
+    }
+
+    pub fn add_port(&self, port: Port) {
+        let imp = self.imp();
+        imp.ports.borrow_mut().insert(port);
+        imp.update_ports();
+    }
+
+    pub fn remove_port(&self, port: &Port) {
+        let imp = self.imp();
+        if imp.ports.borrow_mut().remove(port) {
+            imp.update_ports();
+        } else {
+            log::warn!("Tried to remove non-existant port widget from node");
+        }
+    }
+}

src/ui/graph/node.ui

@@ -0,0 +1,56 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<interface>
+  <requires lib="gtk" version="4.0"/>
+  <template class="HelvumNode" parent="GtkWidget">
+    <style>
+      <class name="card"></class>
+    </style>>
+    <child>
+      <object class="GtkBox">
+        <property name="orientation">vertical</property>
+        <child>
+          <object class="GtkBox">
+            <style>
+              <class name="node-title"></class>
+            </style>
+            <property name="orientation">vertical</property>
+            <property name="spacing">1</property>
+            <child>
+              <object class="GtkLabel" id="node_name">
+                <style>
+                  <class name="heading"></class>
+                </style>
+                <property name="wrap">true</property>
+                <property name="ellipsize">PANGO_ELLIPSIZE_END</property>
+                <property name="lines">2</property>
+                <property name="max-width-chars">20</property>
+              </object>
+            </child>
+            <child>
+              <object class="GtkLabel" id="media_name">
+                <style>
+                  <class name="dim-label"></class>
+                  <class name="caption"></class>
+                </style>
+                <property name="visible">false</property>
+                <property name="wrap">true</property>
+                <property name="ellipsize">PANGO_ELLIPSIZE_END</property>
+                <property name="lines">2</property>
+                <property name="max-width-chars">20</property>
+              </object>
+            </child>
+          </object>
+        </child>
+        <child>
+          <object class="GtkSeparator" id="separator">
+            <!-- The node will show the seperator only once ports are added to it -->
+            <property name="visible">false</property>
+          </object>
+        </child>
+        <child>
+          <object class="GtkGrid" id="port_grid"></object>
+        </child>
+      </object>
+    </child>
+  </template>
+</interface>

src/ui/graph/port.rs

@@ -0,0 +1,364 @@
+// Copyright 2021 Tom A. Wagner <tom.a.wagner@protonmail.com>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License version 3 as published by
+// the Free Software Foundation.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+// SPDX-License-Identifier: GPL-3.0-only
+
+use adw::{
+    gdk,
+    glib::{self, subclass::Signal},
+    gtk::{self, graphene},
+    prelude::*,
+    subclass::prelude::*,
+};
+use pipewire::spa::utils::Direction;
+
+use super::PortHandle;
+
+mod imp {
+    use super::*;
+
+    use std::cell::{Cell, OnceCell};
+
+    use once_cell::sync::Lazy;
+    use pipewire::spa::{param::format::MediaType, utils::Direction};
+
+    /// Graphical representation of a pipewire port.
+    #[derive(gtk::CompositeTemplate, glib::Properties)]
+    #[properties(wrapper_type = super::Port)]
+    #[template(file = "port.ui")]
+    pub struct Port {
+        #[property(get, set, construct_only)]
+        pub(super) pipewire_id: OnceCell<u32>,
+        #[property(
+            type = u32,
+            get = |_| self.media_type.get().as_raw(),
+            set = Self::set_media_type
+        )]
+        pub(super) media_type: Cell<MediaType>,
+        #[property(
+            type = u32,
+            get = |_| self.direction.get().as_raw(),
+            set = Self::set_direction,
+            construct_only
+        )]
+        pub(super) direction: Cell<Direction>,
+        #[property(
+            name = "name", type = String,
+            get = |this: &Self| this.label.text().to_string(),
+            set = |this: &Self, val| {
+                this.label.set_text(val);
+                this.label.set_tooltip_text(Some(val));
+            }
+        )]
+        #[template_child]
+        pub(super) label: TemplateChild<gtk::Label>,
+        #[template_child]
+        pub(super) handle: TemplateChild<PortHandle>,
+    }
+
+    impl Default for Port {
+        fn default() -> Self {
+            Self {
+                pipewire_id: OnceCell::default(),
+                media_type: Cell::new(MediaType::Unknown),
+                direction: Cell::new(Direction::Output),
+                label: TemplateChild::default(),
+                handle: TemplateChild::default(),
+            }
+        }
+    }
+
+    #[glib::object_subclass]
+    impl ObjectSubclass for Port {
+        const NAME: &'static str = "HelvumPort";
+        type Type = super::Port;
+        type ParentType = gtk::Widget;
+
+        fn class_init(klass: &mut Self::Class) {
+            klass.set_css_name("port");
+
+            klass.bind_template();
+        }
+
+        fn instance_init(obj: &glib::subclass::InitializingObject<Self>) {
+            obj.init_template();
+        }
+    }
+
+    #[glib::derived_properties]
+    impl ObjectImpl for Port {
+        fn constructed(&self) {
+            self.parent_constructed();
+
+            // Force left-to-right direction for the ports grid to avoid messed up UI when defaulting to right-to-left
+            self.obj().set_direction(gtk::TextDirection::Ltr);
+
+            // Display a grab cursor when the mouse is over the port so the user knows it can be dragged to another port.
+            self.obj()
+                .set_cursor(gtk::gdk::Cursor::from_name("grab", None).as_ref());
+
+            self.setup_port_drag_and_drop();
+        }
+
+        fn signals() -> &'static [Signal] {
+            static SIGNALS: Lazy<Vec<Signal>> = Lazy::new(|| {
+                vec![Signal::builder("port-toggled")
+                    // Provide id of output port and input port to signal handler.
+                    .param_types([<u32>::static_type(), <u32>::static_type()])
+                    .build()]
+            });
+
+            SIGNALS.as_ref()
+        }
+    }
+
+    impl WidgetImpl for Port {
+        fn measure(&self, orientation: gtk::Orientation, for_size: i32) -> (i32, i32, i32, i32) {
+            match orientation {
+                gtk::Orientation::Horizontal => {
+                    let (min_handle_width, nat_handle_width, _, _) =
+                        self.handle.measure(orientation, for_size);
+                    let (min_label_width, nat_label_width, _, _) = self
+                        .label
+                        .measure(orientation, i32::max(for_size - (nat_handle_width / 2), -1));
+
+                    (
+                        (min_handle_width / 2) + min_label_width,
+                        (nat_handle_width / 2) + nat_label_width,
+                        -1,
+                        -1,
+                    )
+                }
+                gtk::Orientation::Vertical => {
+                    let (min_label_height, nat_label_height, _, _) =
+                        self.label.measure(orientation, for_size);
+                    let (min_handle_height, nat_handle_height, _, _) =
+                        self.handle.measure(orientation, for_size);
+
+                    (
+                        i32::max(min_label_height, min_handle_height),
+                        i32::max(nat_label_height, nat_handle_height),
+                        -1,
+                        -1,
+                    )
+                }
+                _ => unimplemented!(),
+            }
+        }
+
+        fn size_allocate(&self, width: i32, height: i32, _baseline: i32) {
+            let (_, nat_handle_height, _, _) =
+                self.handle.measure(gtk::Orientation::Vertical, height);
+            let (_, nat_handle_width, _, _) =
+                self.handle.measure(gtk::Orientation::Horizontal, width);
+
+            match Direction::from_raw(self.obj().direction()) {
+                Direction::Input => {
+                    let alloc = gtk::Allocation::new(
+                        -nat_handle_width / 2,
+                        (height - nat_handle_height) / 2,
+                        nat_handle_width,
+                        nat_handle_height,
+                    );
+                    self.handle.size_allocate(&alloc, -1);
+
+                    let alloc = gtk::Allocation::new(
+                        nat_handle_width / 2,
+                        0,
+                        width - (nat_handle_width / 2),
+                        height,
+                    );
+                    self.label.size_allocate(&alloc, -1);
+                }
+                Direction::Output => {
+                    let alloc = gtk::Allocation::new(
+                        width - (nat_handle_width / 2),
+                        (height - nat_handle_height) / 2,
+                        nat_handle_width,
+                        nat_handle_height,
+                    );
+                    self.handle.size_allocate(&alloc, -1);
+
+                    let alloc = gtk::Allocation::new(0, 0, width - (nat_handle_width / 2), height);
+                    self.label.size_allocate(&alloc, -1);
+                }
+                _ => unreachable!(),
+            }
+        }
+    }
+
+    impl Port {
+        fn setup_port_drag_and_drop(&self) {
+            let obj = &*self.obj();
+
+            // Add a drag source and drop target controller with the type depending on direction,
+            // they will be responsible for link creation by dragging an output port onto an input port or the other way around.
+            // The port will simply provide its pipewire id to the drag target.
+            // The drop target will accept the source port and use it to emit its `port-toggled` signal.
+
+            // FIXME: We should protect against different media types, e.g. it should not be possible to drop a video port on an audio port.
+
+            let drag_src = gtk::DragSource::builder()
+                .content(&gdk::ContentProvider::for_value(&obj.to_value()))
+                .build();
+            // Override the default drag icon with an empty one so that only a grab cursor is shown.
+            // The graph will render a link from the source port to the cursor to visualize the drag instead.
+            drag_src.set_icon(Some(&gdk::Paintable::new_empty(0, 0)), 0, 0);
+            drag_src.connect_drag_begin(|drag_source, _| {
+                let port = drag_source
+                    .widget()
+                    .dynamic_cast::<super::Port>()
+                    .expect("Widget should be a Port");
+
+                log::trace!("Drag started from port {}", port.pipewire_id());
+            });
+            drag_src.connect_drag_cancel(|drag_source, _, _| {
+                let port = drag_source
+                    .widget()
+                    .dynamic_cast::<super::Port>()
+                    .expect("Widget should be a Port");
+
+                log::trace!("Drag from port {} was cancelled", port.pipewire_id());
+
+                false
+            });
+            obj.add_controller(drag_src);
+
+            let drop_target =
+                gtk::DropTarget::new(super::Port::static_type(), gdk::DragAction::COPY);
+            drop_target.set_preload(true);
+            drop_target.connect_value_notify(|drop_target| {
+                let port = drop_target
+                    .widget()
+                    .dynamic_cast::<super::Port>()
+                    .expect("Widget should be a Port");
+
+                let Some(value) = drop_target.value() else {
+                    return;
+                };
+
+                let other_port: super::Port = value.get().expect("Drop value should be a port");
+
+                // Disallow drags between two ports that have the same direction
+                if !port.is_linkable_to(&other_port) {
+                    // FIXME: For some reason, this prints error:
+                    //        "gdk_drop_get_actions: assertion 'GDK_IS_DROP (self)' failed"
+                    drop_target.reject();
+                }
+            });
+            drop_target.connect_drop(|drop_target, val, _, _| {
+                let port = drop_target
+                    .widget()
+                    .dynamic_cast::<super::Port>()
+                    .expect("Widget should be a Port");
+                let other_port = val
+                    .get::<super::Port>()
+                    .expect("Dropped value should be a Port");
+
+                // Do not accept a drop between imcompatible ports
+                if !port.is_linkable_to(&other_port) {
+                    log::warn!("Tried to link incompatible ports");
+                    return false;
+                }
+
+                let (output_port, input_port) = match Direction::from_raw(port.direction()) {
+                    Direction::Output => (&port, &other_port),
+                    Direction::Input => (&other_port, &port),
+                    _ => unreachable!(),
+                };
+
+                port.emit_by_name::<()>(
+                    "port-toggled",
+                    &[&output_port.pipewire_id(), &input_port.pipewire_id()],
+                );
+
+                true
+            });
+            obj.add_controller(drop_target);
+        }
+
+        fn set_media_type(&self, media_type: u32) {
+            let media_type = MediaType::from_raw(media_type);
+
+            self.media_type.set(media_type);
+
+            for css_class in ["video", "audio", "midi"] {
+                self.handle.remove_css_class(css_class)
+            }
+
+            // Color the port according to its media type.
+            match media_type {
+                MediaType::Video => self.handle.add_css_class("video"),
+                MediaType::Audio => self.handle.add_css_class("audio"),
+                MediaType::Application | MediaType::Stream => self.handle.add_css_class("midi"),
+                _ => {}
+            }
+        }
+
+        fn set_direction(&self, direction: u32) {
+            let direction = Direction::from_raw(direction);
+
+            self.direction.set(direction);
+
+            match direction {
+                Direction::Input => {
+                    self.obj().set_halign(gtk::Align::Start);
+                    self.label.set_halign(gtk::Align::Start);
+                }
+                Direction::Output => {
+                    self.obj().set_halign(gtk::Align::End);
+                    self.label.set_halign(gtk::Align::End);
+                }
+                _ => unreachable!(),
+            }
+        }
+    }
+}
+
+glib::wrapper! {
+    pub struct Port(ObjectSubclass<imp::Port>)
+        @extends gtk::Widget;
+}
+
+impl Port {
+    pub fn new(id: u32, name: &str, direction: Direction) -> Self {
+        glib::Object::builder()
+            .property("pipewire-id", id)
+            .property("direction", direction.as_raw())
+            .property("name", name)
+            .build()
+    }
+
+    pub fn link_anchor(&self) -> graphene::Point {
+        let style_context = self.style_context();
+        let padding_right: f32 = style_context.padding().right().into();
+        let border_right: f32 = style_context.border().right().into();
+        let padding_left: f32 = style_context.padding().left().into();
+        let border_left: f32 = style_context.border().left().into();
+
+        let direction = Direction::from_raw(self.direction());
+        graphene::Point::new(
+            match direction {
+                Direction::Output => self.width() as f32 + padding_right + border_right,
+                Direction::Input => 0.0 - padding_left - border_left,
+                _ => unreachable!(),
+            },
+            self.height() as f32 / 2.0,
+        )
+    }
+
+    pub fn is_linkable_to(&self, other_port: &Self) -> bool {
+        self.direction() != other_port.direction()
+    }
+}

src/ui/graph/port.ui

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<interface>
+  <requires lib="gtk" version="4.0"/>
+  <template class="HelvumPort" parent="GtkWidget">
+    <property name="hexpand">true</property>
+    <child>
+      <object class="GtkLabel" id="label">
+        <property name="wrap">true</property>
+        <property name="ellipsize">PANGO_ELLIPSIZE_END</property>
+        <property name="lines">2</property>
+        <property name="max-width-chars">20</property>
+      </object>
+    </child>
+    <child>
+      <object class="HelvumPortHandle" id="handle"></object>
+    </child>
+  </template>
+</interface>
+

src/ui/graph/port_handle.rs

@@ -0,0 +1,84 @@
+// Copyright 2021 Tom A. Wagner <tom.a.wagner@protonmail.com>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License version 3 as published by
+// the Free Software Foundation.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+// SPDX-License-Identifier: GPL-3.0-only
+
+use adw::{glib, gtk, prelude::*, subclass::prelude::*};
+
+mod imp {
+    use super::*;
+
+    #[derive(Default)]
+    pub struct PortHandle {}
+
+    #[glib::object_subclass]
+    impl ObjectSubclass for PortHandle {
+        const NAME: &'static str = "HelvumPortHandle";
+        type Type = super::PortHandle;
+        type ParentType = gtk::Widget;
+
+        fn class_init(klass: &mut Self::Class) {
+            klass.set_css_name("port-handle");
+        }
+    }
+
+    impl ObjectImpl for PortHandle {
+        fn constructed(&self) {
+            self.parent_constructed();
+
+            let obj = &*self.obj();
+
+            obj.set_halign(gtk::Align::Center);
+            obj.set_valign(gtk::Align::Center);
+        }
+    }
+
+    impl WidgetImpl for PortHandle {
+        fn request_mode(&self) -> gtk::SizeRequestMode {
+            gtk::SizeRequestMode::ConstantSize
+        }
+
+        fn measure(&self, _orientation: gtk::Orientation, _for_size: i32) -> (i32, i32, i32, i32) {
+            (Self::HANDLE_SIZE, Self::HANDLE_SIZE, -1, -1)
+        }
+    }
+
+    impl PortHandle {
+        pub const HANDLE_SIZE: i32 = 14;
+    }
+}
+
+glib::wrapper! {
+    pub struct PortHandle(ObjectSubclass<imp::PortHandle>)
+        @extends gtk::Widget;
+}
+
+impl PortHandle {
+    pub fn new() -> Self {
+        glib::Object::new()
+    }
+
+    pub fn get_link_anchor(&self) -> gtk::graphene::Point {
+        gtk::graphene::Point::new(
+            imp::PortHandle::HANDLE_SIZE as f32 / 2.0,
+            imp::PortHandle::HANDLE_SIZE as f32 / 2.0,
+        )
+    }
+}
+
+impl Default for PortHandle {
+    fn default() -> Self {
+        Self::new()
+    }
+}

src/ui/graph/zoomentry.rs

@@ -1,6 +1,6 @@
-use gtk::{glib, prelude::*, subclass::prelude::*};
+use adw::{glib, gtk, prelude::*, subclass::prelude::*};
 
-use crate::view;
+use super::GraphView;
 
 mod imp {
     use std::cell::RefCell;
@@ -13,7 +13,7 @@ mod imp {
     #[derive(gtk::CompositeTemplate)]
     #[template(file = "zoomentry.ui")]
     pub struct ZoomEntry {
-        pub graphview: RefCell<Option<view::GraphView>>,
+        pub graphview: RefCell<Option<GraphView>>,
         #[template_child]
         pub zoom_out_button: TemplateChild<gtk::Button>,
         #[template_child]
@@ -34,6 +34,7 @@ mod imp {
             menu.append(Some("200%"), Some("win.set-zoom(2.0)"));
             menu.append(Some("300%"), Some("win.set-zoom(3.0)"));
             let popover = gtk::PopoverMenu::from_model(Some(&menu));
+            popover.set_position(gtk::PositionType::Top);
 
             ZoomEntry {
                 graphview: Default::default(),
@@ -109,11 +110,9 @@ mod imp {
 
         fn properties() -> &'static [glib::ParamSpec] {
             static PROPERTIES: Lazy<Vec<glib::ParamSpec>> = Lazy::new(|| {
-                vec![
+                vec![glib::ParamSpecObject::builder::<GraphView>("zoomed-widget")
-                    glib::ParamSpecObject::builder::<view::GraphView>("zoomed-widget")
+                    .flags(glib::ParamFlags::READWRITE | glib::ParamFlags::CONSTRUCT)
-                        .flags(glib::ParamFlags::READWRITE | glib::ParamFlags::CONSTRUCT)
+                    .build()]
-                        .build(),
-                ]
             });
 
             PROPERTIES.as_ref()
@@ -129,15 +128,17 @@ mod imp {
         fn set_property(&self, _id: usize, value: &glib::Value, pspec: &glib::ParamSpec) {
             match pspec.name() {
                 "zoomed-widget" => {
-                    let widget: view::GraphView = value.get().unwrap();
+                    let widget: Option<GraphView> = value.get().unwrap();
-                    widget.connect_notify_local(
+                    if let Some(ref widget) = widget {
-                        Some("zoom-factor"),
+                        widget.connect_notify_local(
-                        clone!(@weak self as imp => move |graphview, _| {
+                            Some("zoom-factor"),
-                            imp.update_zoom_factor_text(graphview.zoom_factor());
+                            clone!(@weak self as imp => move |graphview, _| {
-                        }),
+                                imp.update_zoom_factor_text(graphview.zoom_factor());
-                    );
+                            }),
-                    self.update_zoom_factor_text(widget.zoom_factor());
+                        );
-                    *self.graphview.borrow_mut() = Some(widget);
+                        self.update_zoom_factor_text(widget.zoom_factor());
+                    }
+                    *self.graphview.borrow_mut() = widget;
                 }
                 _ => unimplemented!(),
             }
@@ -149,11 +150,11 @@ mod imp {
     impl ZoomEntry {
         /// Update the text contained in the combobox's entry to reflect the provided zoom factor.
         ///
-        /// This does not update the associated [`view::GraphView`]s zoom level.
+        /// This does not update the associated [`GraphView`]s zoom level.
         fn update_zoom_factor_text(&self, zoom_factor: f64) {
             self.entry
                 .buffer()
-                .set_text(&format!("{factor:.0}%", factor = zoom_factor * 100.));
+                .set_text(format!("{factor:.0}%", factor = zoom_factor * 100.));
         }
     }
 }
@@ -164,7 +165,7 @@ glib::wrapper! {
 }
 
 impl ZoomEntry {
-    pub fn new(zoomed_widget: &view::GraphView) -> Self {
+    pub fn new(zoomed_widget: &GraphView) -> Self {
         glib::Object::builder()
             .property("zoomed-widget", zoomed_widget)
             .build()

src/ui/graph/zoomentry.ui

@@ -1,26 +1,37 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <interface>
   <template class="HelvumZoomEntry" parent="GtkBox">
-    <child>
+    <property name="spacing">12</property>
-      <object class="GtkButton" id="zoom_out_button">
-        <property name="icon-name">zoom-out-symbolic</property>
-        <property name="tooltip-text">Zoom out</property>
-      </object>
-    </child>
     <child>
       <object class="GtkEntry" id="entry">
         <property name="secondary-icon-name">go-down-symbolic</property>
         <property name="input-purpose">digits</property>
+        <property name="max-width-chars">5</property>
+        <style>
+          <class name="osd"/>
+          <class name="rounded"/>
+        </style>
+      </object>
+    </child>
+    <child>
+      <object class="GtkButton" id="zoom_out_button">
+        <property name="icon-name">zoom-out-symbolic</property>
+        <property name="tooltip-text">Zoom out</property>
+        <style>
+          <class name="osd"/>
+          <class name="rounded"/>
+        </style>
       </object>
     </child>
     <child>
       <object class="GtkButton" id="zoom_in_button">
         <property name="icon-name">zoom-in-symbolic</property>
         <property name="tooltip-text">Zoom in</property>
+        <style>
+          <class name="osd"/>
+          <class name="rounded"/>
+        </style>
       </object>
     </child>
-    <style>
-      <class name="linked"/>
-    </style>
   </template>
 </interface>

src/ui/mod.rs

@@ -18,12 +18,7 @@
 //!
 //! This module contains gtk widgets needed to present the graphical user interface.
 
-mod graph_view;
+pub mod graph;
-mod node;
-mod port;
-mod zoomentry;
 
-pub use graph_view::GraphView;
+mod window;
-pub use node::Node;
+pub use window::*;
-pub use port::Port;
-pub use zoomentry::ZoomEntry;

src/ui/window.rs

@@ -0,0 +1,65 @@
+use adw::{gio, gtk, prelude::*, subclass::prelude::*};
+
+use super::graph;
+
+mod imp {
+    use super::*;
+
+    #[derive(Default, gtk::CompositeTemplate, glib::Properties)]
+    #[properties(wrapper_type = super::Window)]
+    #[template(file = "window.ui")]
+    pub struct Window {
+        #[template_child]
+        pub header_bar: TemplateChild<adw::HeaderBar>,
+        #[template_child]
+        #[property(type = adw::Banner, get = |_| self.connection_banner.clone())]
+        pub connection_banner: TemplateChild<adw::Banner>,
+        #[template_child]
+        #[property(type = graph::GraphView, get = |_| self.graph.clone())]
+        pub graph: TemplateChild<graph::GraphView>,
+    }
+
+    #[glib::object_subclass]
+    impl ObjectSubclass for Window {
+        const NAME: &'static str = "HelvumWindow";
+        type Type = super::Window;
+        type ParentType = adw::ApplicationWindow;
+
+        fn class_init(klass: &mut Self::Class) {
+            // Ensure custom types are registered
+            graph::GraphView::ensure_type();
+            graph::ZoomEntry::ensure_type();
+
+            klass.bind_template();
+        }
+
+        fn instance_init(obj: &glib::subclass::InitializingObject<Self>) {
+            obj.init_template();
+        }
+    }
+
+    #[glib::derived_properties]
+    impl ObjectImpl for Window {}
+    impl WidgetImpl for Window {}
+    impl WindowImpl for Window {}
+    impl ApplicationWindowImpl for Window {}
+    impl AdwApplicationWindowImpl for Window {}
+}
+
+glib::wrapper! {
+    pub struct Window(ObjectSubclass<imp::Window>)
+        @extends adw::ApplicationWindow, gtk::ApplicationWindow, gtk::Window, gtk::Widget,
+        @implements gio::ActionGroup, gio::ActionMap;
+}
+
+impl Window {
+    pub fn new() -> Self {
+        glib::Object::new()
+    }
+}
+
+impl Default for Window {
+    fn default() -> Self {
+        Self::new()
+    }
+}

src/ui/window.ui

@@ -0,0 +1,66 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<interface>
+  <requires lib="gtk" version="4.0"/>
+  <requires lib="Adw" version="1.4"/>
+  <menu id="primary_menu">
+    <section>
+      <item>
+        <attribute name="label">_About Helvum</attribute>
+        <attribute name="action">app.about</attribute>
+      </item>
+    </section>
+  </menu>
+  <template class="HelvumWindow" parent="AdwApplicationWindow">
+    <property name="default-width">1280</property>
+    <property name="default-height">720</property>
+    <property name="title">Helvum - Pipewire Patchbay</property>
+    <child>
+      <object class="AdwToolbarView">
+        <child type="top">
+          <object class="AdwHeaderBar" id="header_bar">
+            <child type="end">
+              <object class="GtkMenuButton">
+                <property name="icon-name">open-menu-symbolic</property>
+                <property name="menu-model">primary_menu</property>
+              </object>
+            </child>
+          </object>
+        </child>
+        <property name="content">
+          <object class="GtkBox">
+            <property name="orientation">vertical</property>
+            <child>
+              <object class="AdwBanner" id="connection_banner">
+                <property name="title" translatable="yes">Disconnected</property>
+                <property name="revealed">false</property>
+              </object>
+            </child>
+            <child>
+              <object class="GtkOverlay">
+                <child>
+                  <object class="GtkScrolledWindow">
+                    <child>
+                      <object class="HelvumGraphView" id="graph">
+                        <property name="hexpand">true</property>
+                        <property name="vexpand">true</property>
+                      </object>
+                    </child>
+                  </object>
+                </child>
+                <child type="overlay">
+                  <object class="HelvumZoomEntry">
+                    <property name="zoomed-widget">graph</property>
+                    <property name="halign">end</property>
+                    <property name="valign">end</property>
+                    <property name="margin-end">24</property>
+                    <property name="margin-bottom">24</property>
+                  </object>
+                </child>
+              </object>
+            </child>
+          </object>
+        </property>
+      </object>
+    </child>
+  </template>
+</interface>

src/view/node.rs

@@ -1,179 +0,0 @@
-// Copyright 2021 Tom A. Wagner <tom.a.wagner@protonmail.com>
-//
-// This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License version 3 as published by
-// the Free Software Foundation.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License
-// along with this program.  If not, see <http://www.gnu.org/licenses/>.
-//
-// SPDX-License-Identifier: GPL-3.0-only
-
-use gtk::{glib, prelude::*, subclass::prelude::*};
-use pipewire::spa::Direction;
-
-use std::collections::HashMap;
-
-mod imp {
-    use glib::ParamFlags;
-    use once_cell::sync::Lazy;
-
-    use super::*;
-
-    use std::cell::{Cell, RefCell};
-
-    pub struct Node {
-        pub(super) pipewire_id: Cell<u32>,
-        pub(super) grid: gtk::Grid,
-        pub(super) label: gtk::Label,
-        pub(super) ports: RefCell<HashMap<u32, crate::view::port::Port>>,
-        pub(super) num_ports_in: Cell<i32>,
-        pub(super) num_ports_out: Cell<i32>,
-    }
-
-    #[glib::object_subclass]
-    impl ObjectSubclass for Node {
-        const NAME: &'static str = "HelvumNode";
-        type Type = super::Node;
-        type ParentType = gtk::Widget;
-
-        fn class_init(klass: &mut Self::Class) {
-            klass.set_layout_manager_type::<gtk::BinLayout>();
-        }
-
-        fn new() -> Self {
-            let grid = gtk::Grid::new();
-
-            let label = gtk::Label::new(None);
-            label.set_wrap(true);
-            label.set_lines(2);
-            label.set_max_width_chars(20);
-            label.set_ellipsize(gtk::pango::EllipsizeMode::End);
-
-            grid.attach(&label, 0, 0, 2, 1);
-
-            // Display a grab cursor when the mouse is over the label so the user knows the node can be dragged.
-            label.set_cursor(gtk::gdk::Cursor::from_name("grab", None).as_ref());
-
-            Self {
-                pipewire_id: Cell::new(0),
-                grid,
-                label,
-                ports: RefCell::new(HashMap::new()),
-                num_ports_in: Cell::new(0),
-                num_ports_out: Cell::new(0),
-            }
-        }
-    }
-
-    impl ObjectImpl for Node {
-        fn constructed(&self) {
-            self.parent_constructed();
-            self.grid.set_parent(&*self.obj());
-        }
-
-        fn properties() -> &'static [glib::ParamSpec] {
-            static PROPERTIES: Lazy<Vec<glib::ParamSpec>> = Lazy::new(|| {
-                vec![
-                    glib::ParamSpecUInt::builder("pipewire-id")
-                        .flags(ParamFlags::READWRITE | ParamFlags::CONSTRUCT_ONLY)
-                        .build(),
-                    glib::ParamSpecString::builder("name").build(),
-                ]
-            });
-
-            PROPERTIES.as_ref()
-        }
-
-        fn property(&self, _id: usize, pspec: &glib::ParamSpec) -> glib::Value {
-            match pspec.name() {
-                "pipewire-id" => self.pipewire_id.get().to_value(),
-                "name" => self.label.text().to_value(),
-                _ => unimplemented!(),
-            }
-        }
-
-        fn set_property(&self, _id: usize, value: &glib::Value, pspec: &glib::ParamSpec) {
-            match pspec.name() {
-                "name" => {
-                    self.label.set_text(value.get().unwrap());
-                    self.label.set_tooltip_text(value.get().ok());
-                }
-                "pipewire-id" => self.pipewire_id.set(value.get().unwrap()),
-                _ => unimplemented!(),
-            }
-        }
-
-        fn dispose(&self) {
-            self.grid.unparent();
-        }
-    }
-
-    impl WidgetImpl for Node {}
-}
-
-glib::wrapper! {
-    pub struct Node(ObjectSubclass<imp::Node>)
-        @extends gtk::Widget;
-}
-
-impl Node {
-    pub fn new(name: &str, pipewire_id: u32) -> Self {
-        glib::Object::builder()
-            .property("name", &name)
-            .property("pipewire-id", &pipewire_id)
-            .build()
-    }
-
-    pub fn pipewire_id(&self) -> u32 {
-        self.property("pipewire-id")
-    }
-
-    /// Get the nodes `name` property, which represents the displayed name.
-    pub fn name(&self) -> String {
-        self.property("name")
-    }
-
-    /// Set the nodes `name` property, which represents the displayed name.
-    pub fn set_name(&self, name: &str) {
-        self.set_property("name", name);
-    }
-
-    pub fn add_port(&mut self, id: u32, port: super::port::Port) {
-        let imp = self.imp();
-
-        match port.direction() {
-            Direction::Input => {
-                imp.grid.attach(&port, 0, imp.num_ports_in.get() + 1, 1, 1);
-                imp.num_ports_in.set(imp.num_ports_in.get() + 1);
-            }
-            Direction::Output => {
-                imp.grid.attach(&port, 1, imp.num_ports_out.get() + 1, 1, 1);
-                imp.num_ports_out.set(imp.num_ports_out.get() + 1);
-            }
-        }
-
-        imp.ports.borrow_mut().insert(id, port);
-    }
-
-    pub fn get_port(&self, id: u32) -> Option<super::port::Port> {
-        self.imp().ports.borrow_mut().get(&id).cloned()
-    }
-
-    pub fn remove_port(&self, id: u32) {
-        let imp = self.imp();
-        if let Some(port) = imp.ports.borrow_mut().remove(&id) {
-            match port.direction() {
-                Direction::Input => imp.num_ports_in.set(imp.num_ports_in.get() - 1),
-                Direction::Output => imp.num_ports_in.set(imp.num_ports_out.get() - 1),
-            }
-
-            port.unparent();
-        }
-    }
-}

src/view/port.rs

@@ -1,249 +0,0 @@
-// Copyright 2021 Tom A. Wagner <tom.a.wagner@protonmail.com>
-//
-// This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License version 3 as published by
-// the Free Software Foundation.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License
-// along with this program.  If not, see <http://www.gnu.org/licenses/>.
-//
-// SPDX-License-Identifier: GPL-3.0-only
-
-use gtk::{
-    gdk,
-    glib::{self, clone, subclass::Signal},
-    prelude::*,
-    subclass::prelude::*,
-};
-use log::{trace, warn};
-use pipewire::spa::Direction;
-
-use crate::MediaType;
-
-/// A helper struct for linking a output port to an input port.
-/// It carries the output ports id.
-#[derive(Clone, Debug, glib::Boxed)]
-#[boxed_type(name = "HelvumForwardLink")]
-struct ForwardLink(u32);
-
-/// A helper struct for linking an input to an output port.
-/// It carries the input ports id.
-#[derive(Clone, Debug, glib::Boxed)]
-#[boxed_type(name = "HelvumReversedLink")]
-struct ReversedLink(u32);
-
-mod imp {
-    use glib::ParamFlags;
-    use once_cell::{sync::Lazy, unsync::OnceCell};
-    use pipewire::spa::Direction;
-
-    use super::*;
-
-    /// Graphical representation of a pipewire port.
-    #[derive(Default)]
-    pub struct Port {
-        pub(super) pipewire_id: OnceCell<u32>,
-        pub(super) label: gtk::Label,
-        pub(super) direction: OnceCell<Direction>,
-    }
-
-    #[glib::object_subclass]
-    impl ObjectSubclass for Port {
-        const NAME: &'static str = "HelvumPort";
-        type Type = super::Port;
-        type ParentType = gtk::Widget;
-
-        fn class_init(klass: &mut Self::Class) {
-            klass.set_layout_manager_type::<gtk::BinLayout>();
-
-            // Make it look like a GTK button.
-            klass.set_css_name("button");
-        }
-    }
-
-    impl ObjectImpl for Port {
-        fn constructed(&self) {
-            self.parent_constructed();
-
-            self.label.set_parent(&*self.obj());
-            self.label.set_wrap(true);
-            self.label.set_lines(2);
-            self.label.set_max_width_chars(20);
-            self.label.set_ellipsize(gtk::pango::EllipsizeMode::End);
-        }
-
-        fn dispose(&self) {
-            self.label.unparent()
-        }
-
-        fn properties() -> &'static [glib::ParamSpec] {
-            static PROPERTIES: Lazy<Vec<glib::ParamSpec>> = Lazy::new(|| {
-                vec![
-                    glib::ParamSpecUInt::builder("pipewire-id")
-                        .flags(ParamFlags::READWRITE | ParamFlags::CONSTRUCT_ONLY)
-                        .build(),
-                    glib::ParamSpecString::builder("name").build(),
-                ]
-            });
-
-            PROPERTIES.as_ref()
-        }
-
-        fn property(&self, _id: usize, pspec: &glib::ParamSpec) -> glib::Value {
-            match pspec.name() {
-                "pipewire-id" => self.pipewire_id.get().unwrap().to_value(),
-                "name" => self.label.text().to_value(),
-                _ => unimplemented!(),
-            }
-        }
-
-        fn set_property(&self, _id: usize, value: &glib::Value, pspec: &glib::ParamSpec) {
-            match pspec.name() {
-                "name" => {
-                    self.label.set_text(value.get().unwrap());
-                    self.label.set_tooltip_text(value.get().ok());
-                }
-                "pipewire-id" => self.pipewire_id.set(value.get().unwrap()).unwrap(),
-                _ => unimplemented!(),
-            }
-        }
-
-        fn signals() -> &'static [Signal] {
-            static SIGNALS: Lazy<Vec<Signal>> = Lazy::new(|| {
-                vec![Signal::builder("port-toggled")
-                    // Provide id of output port and input port to signal handler.
-                    .param_types([<u32>::static_type(), <u32>::static_type()])
-                    .build()]
-            });
-
-            SIGNALS.as_ref()
-        }
-    }
-    impl WidgetImpl for Port {}
-}
-
-glib::wrapper! {
-    pub struct Port(ObjectSubclass<imp::Port>)
-        @extends gtk::Widget;
-}
-
-impl Port {
-    pub fn new(id: u32, name: &str, direction: Direction, media_type: Option<MediaType>) -> Self {
-        // Create the widget and initialize needed fields
-        let res: Self = glib::Object::builder()
-            .property("pipewire-id", &id)
-            .property("name", &name)
-            .build();
-
-        let imp = res.imp();
-
-        imp.direction
-            .set(direction)
-            .expect("Port direction already set");
-
-        // Add a drag source and drop target controller with the type depending on direction,
-        // they will be responsible for link creation by dragging an output port onto an input port or the other way around.
-
-        // FIXME: We should protect against different media types, e.g. it should not be possible to drop a video port on an audio port.
-
-        // The port will simply provide its pipewire id to the drag target.
-        let drag_src = gtk::DragSource::builder()
-            .content(&gdk::ContentProvider::for_value(&match direction {
-                Direction::Input => ReversedLink(id).to_value(),
-                Direction::Output => ForwardLink(id).to_value(),
-            }))
-            .build();
-        drag_src.connect_drag_begin(move |_, _| {
-            trace!("Drag started from port {}", id);
-        });
-        drag_src.connect_drag_cancel(move |_, _, _| {
-            trace!("Drag from port {} was cancelled", id);
-            false
-        });
-        res.add_controller(drag_src);
-
-        // The drop target will accept either a `ForwardLink` or `ReversedLink` depending in its own direction,
-        // and use it to emit its `port-toggled` signal.
-        let drop_target = gtk::DropTarget::new(
-            match direction {
-                Direction::Input => ForwardLink::static_type(),
-                Direction::Output => ReversedLink::static_type(),
-            },
-            gdk::DragAction::COPY,
-        );
-        match direction {
-            Direction::Input => {
-                drop_target.connect_drop(
-                    clone!(@weak res as this => @default-panic, move |drop_target, val, _, _| {
-                        if let Ok(ForwardLink(source_id)) = val.get::<ForwardLink>() {
-                            // Get the callback registered in the widget and call it
-                            drop_target
-                                .widget()
-                                .emit_by_name::<()>("port-toggled", &[&source_id, &this.pipewire_id()]);
-                        } else {
-                            warn!("Invalid type dropped on ingoing port");
-                        }
-
-                        true
-                    }),
-                );
-            }
-            Direction::Output => {
-                drop_target.connect_drop(
-                    clone!(@weak res as this => @default-panic, move |drop_target, val, _, _| {
-                        if let Ok(ReversedLink(target_id)) = val.get::<ReversedLink>() {
-                            // Get the callback registered in the widget and call it
-                            drop_target
-                                .widget()
-                                .emit_by_name::<()>("port-toggled", &[&this.pipewire_id(), &target_id]);
-                        } else {
-                            warn!("Invalid type dropped on outgoing port");
-                        }
-
-                        true
-                    }),
-                );
-            }
-        }
-        res.add_controller(drop_target);
-
-        // Display a grab cursor when the mouse is over the port so the user knows it can be dragged to another port.
-        res.set_cursor(gtk::gdk::Cursor::from_name("grab", None).as_ref());
-
-        // Color the port according to its media type.
-        match media_type {
-            Some(MediaType::Video) => res.add_css_class("video"),
-            Some(MediaType::Audio) => res.add_css_class("audio"),
-            Some(MediaType::Midi) => res.add_css_class("midi"),
-            None => {}
-        }
-
-        res
-    }
-
-    pub fn pipewire_id(&self) -> u32 {
-        self.property("pipewire-id")
-    }
-
-    /// Get the nodes `name` property, which represents the displayed name.
-    pub fn name(&self) -> String {
-        self.property("name")
-    }
-
-    /// Set the nodes `name` property, which represents the displayed name.
-    pub fn set_name(&self, name: &str) {
-        self.set_property("name", name);
-    }
-
-    pub fn direction(&self) -> &Direction {
-        self.imp()
-            .direction
-            .get()
-            .expect("Port direction is not set")
-    }
-}